JP2005156846A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the problem generated by lowering of a temporary power source voltage. <P>SOLUTION: A camera stores a power source voltage value Vc in full depression of a shutter button 35, a power source voltage value Ve during driving a shutter 39, and a differential voltage value Vf subtracting the voltage value Ve from the voltage value Vc, respectively, when fully depressing the shutter button 35. After shutter driving, an estimated voltage value Ve', subtracting the differential voltage value Vf from the measured power source voltage value, is compared with a limiting voltage value Vb. When the estimated voltage value Ve' becomes lower than the limit voltage value Vb, the power source voltage value is predicted as becoming lower than the limiting voltage value Vb during the driving of the shutter, when hereafter, the shutter is driven; and after this prediction, driving of the shutter 39 is inhibited. In addition, explaination message informing to this effect is displayed on an LCD 27. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is driven by power supplied from a power source, executes a predetermined photographing process in accordance with the operation of a shutter button, picks up a subject image obtained through a photographing lens, and measures a power source voltage. And a power shut-off means for performing a power shut-off process for stopping the power supply when the measured power-supply voltage value falls below a preset limit voltage value.

  The camera is provided with a shutter button, and in conjunction with the pressing of the shutter button, a predetermined photographing process is executed and imaging is performed. Each unit of the camera is driven by being supplied with power from a power source such as a battery or a built-in battery, and executes a photographing process when the shutter button is pressed.

  Many cameras monitor the power supply voltage to detect the remaining power. When the power supply voltage value decreases to a preset warning voltage value, a power supply voltage value decrease warning is issued, and the power supply voltage value decreases further, and the power supply voltage value decreases to a limit voltage value that can guarantee the drive of the device. Then, in order to stop each part of the camera safely, a power-off process is performed.

  In order to take a picture while paying attention to the remaining amount of power, it is necessary for the user to accurately detect the remaining amount of power and perform warning or power-off processing at an appropriate time. For this reason, the power consumed by examining the number of operations and the operation time of the motor that drives the zoom lens is obtained, and the remaining amount of the power supply is estimated based on the power consumption value and the voltage between the terminals of the power supply. (For example, refer to Patent Document 1 below). In this way, the remaining amount of power can be estimated more accurately, and a warning or power-off process can be performed at an appropriate time.

JP-A-11-282074

  By the way, a phenomenon occurs in which the power supply voltage value temporarily decreases during execution of the photographing process, but the camera described in the above-mentioned patent document does not take measures against such a temporary decrease in power supply voltage value. For this reason, when the shutter button is operated, there is a problem that a warning may be suddenly issued during the photographing process or a power shutdown process may be performed even though the warning is not issued.

  It is an object of the present invention to provide a camera that can prevent a problem that occurs due to a temporary decrease in the power supply voltage value associated with the execution of a photographing process.

  In order to achieve the above object, the camera of the present invention is driven by power supplied from a power source, performs a predetermined photographing process in accordance with the operation of the shutter button, and captures a subject image obtained through the photographing lens. A power supply voltage measuring means for measuring the power supply voltage; and a power supply shutting means for performing a power shutoff process for stopping the supply of the power when the measured power supply voltage value falls below a preset limit voltage value. In the camera, the power supply voltage measurement unit, when it is determined that the power supply voltage value at the time of operating the shutter button is higher than the limit voltage value by a predetermined value or more, and the power supply has a remaining amount necessary for executing the shooting process, It is characterized in that the measurement of the power supply voltage during the execution of the photographing process is interrupted to prevent the power shut-off process during the execution of the photographing process due to a temporary decrease in the power supply voltage accompanying the execution of the photographing process.

  A warning voltage value that is higher than the limit voltage value is set, and when the measured power supply voltage value is lower than the warning voltage value, warning means that issues a warning of a drop in power supply voltage value is provided, and the power supply voltage When the power supply voltage value at the time of operating the shutter button exceeds the warning voltage value, the measurement unit determines that the power supply has a remaining amount necessary for execution of the imaging process, and the power supply voltage value during execution of the imaging process The measurement may be interrupted.

  The camera of the present invention is driven by being supplied with power from a power source, executes a predetermined photographing process in accordance with the operation of the shutter button, picks up a subject image obtained through the photographing lens, and measures a power source voltage. In a camera comprising power supply voltage measuring means and power supply shutting means for performing power shutoff processing for stopping the supply of power when the measured power supply voltage value falls below a preset limit voltage value, When the power supply voltage value is predicted to be lower than the limit voltage value during the next shooting process based on the fluctuation of the power supply voltage value associated with the execution of the shooting process, Prohibiting means for prohibiting execution of the next photographing process, and when the power supply voltage value is predicted to fall below the limit voltage value during execution of the next photographing process by the prohibiting means, It is characterized by providing a notification unit that performs a notification to the effect that the shadow process prohibition.

  The prohibiting means stores the power supply voltage value before execution of the photographing process as a prohibited voltage value when the power shut-off process is performed during the photographing process, and the power supply voltage value at the predicted time point indicates the prohibited voltage value. When the value is lower, it may be predicted that the power supply voltage value is lower than the limit voltage value during the execution of the future photographing process.

  Further, the prohibiting means stores a differential voltage value obtained by subtracting the power supply voltage value during execution of the imaging process from the power supply voltage value before execution of the imaging process, and a value obtained by subtracting the differential voltage value from the power supply voltage value at the prediction time point However, when the voltage is lower than the limit voltage value, the power supply voltage value may be predicted to be lower than the limit voltage value during the execution of a future photographing process.

  Further, the prohibiting means stores a differential voltage value obtained by subtracting the power supply voltage value during execution of the imaging process from the power supply voltage value before execution of the imaging process, and the limit voltage until the future imaging process is executed. When the limit voltage value is changed by adding the estimated value to the value, and the power supply voltage value at the prediction time is lower than the limit voltage value after the change, the power supply voltage value is changed during the future photographing process. It may be predicted that the voltage will fall below the limit voltage value.

  Warning means for issuing a warning of a power supply voltage drop when a warning voltage value that is higher than the limit voltage value is set and the power supply voltage value measured by the power supply voltage measurement means is lower than the warning voltage value The warning means predicts whether or not the power supply voltage value falls below the warning voltage value during the next shooting process based on the fluctuation of the power supply voltage value associated with the execution of the shooting process performed in the past. If it is predicted that the value will be lower, the warning may be performed at the time of prediction.

  In the camera of the present invention, when the power supply voltage value at the time of operating the shutter button is higher than the limit voltage value by a predetermined value or more and it is determined that the power supply has a remaining amount necessary for executing the shooting process, Since the measurement of the power supply voltage is interrupted, it is possible to prevent problems such as a warning being issued during the photographing process and a power-off process being performed.

  Further, the camera of the present invention predicts whether or not the power supply voltage value during the next photographing process is below the limit voltage value based on the fluctuation of the power supply voltage value accompanying the execution of the photographing process performed in the past. If it is predicted that it will be lower than that, the execution of the subsequent photographing process is prohibited and the fact is notified so that the problem that the power shut-off process is suddenly performed during the photographing process can be prevented. .

  Furthermore, it is predicted that the power supply voltage value during the execution of the next photographing process is lower than the warning voltage value based on the fluctuation of the power supply voltage value associated with the execution of the photographing process performed in the past. In such a case, a warning about a drop in the power supply voltage value is issued at the time of prediction, so that it is possible to prevent a problem that a warning is suddenly issued during the shooting process.

  Examples 1 to 4 in which the present invention is applied to a digital camera will be described below.

  1 and 2, a lens barrel 15 that holds the photographing lens 13 is incorporated in the front surface of the digital camera 10, and a strobe light emitting unit 16 is exposed. On the side surface of the digital camera 10, a lid 19 is provided to cover a memory card slot into which a memory card 17 (see FIG. 3) is detachably loaded. In addition, a lid 23 is provided on the bottom surface of the digital camera 10 to cover a battery loading chamber in which a rechargeable battery 20 (see FIG. 3) is loaded.

  An operation unit 25 and a liquid crystal display (LCD) 27 are provided on the back surface of the digital camera 10. The operation unit 25 includes a zoom lever 29, a mode selection switch 30 that switches between a shooting mode, a playback mode, and a menu mode for performing various settings, and a power switch 33. The LCD 27 displays captured images, so-called through images, and various menu screens. Further, as will be described in detail later, the LCD 27 displays a warning message for notifying when the remaining amount of the battery 20 is low, and when the battery 20 is low and the power shut-off process is performed. A notification message for notification is displayed (see FIG. 5).

  A shutter button 35 is provided on the upper surface of the digital camera 10. The shutter button 35 is a two-step push switch. When the shutter button 35 is lightly pressed (half-pressed) during the shooting mode, the flash is charged according to the illuminance of the subject, automatic exposure adjustment (AE), Various shooting preparation processes such as automatic focus adjustment (AF) are performed. In this state, when the shutter button 35 is pressed once more (fully pressed), the main photographing process is performed, and the image signal for one screen is converted into image data, and then various image processes and compression processes are performed. Recorded in the memory card 17.

  In FIG. 3 showing the electrical configuration of the digital camera 10, a diaphragm 37, a shutter 39 and a CCD 40 are arranged side by side behind the taking lens 13. The photographing lens 13 includes a zoom lens 43 and a focus lens 45, to which a zoom motor 47 and a focus motor 49 are connected, respectively. An iris motor 50 is connected to the diaphragm 37, and a shutter motor 53 is connected to the shutter 39.

  The zoom lens 43 is driven by a zoom motor 47. The zoom motor 47 performs zooming by moving the zoom lens 43 to the wide side or the tele side in conjunction with the operation of the zoom lever 29. The focus lens 45 is driven by a focus motor 49. The focus motor 49 moves the focus lens 45 according to the subject distance and the zoom lens 43, and performs focus adjustment so that the photographing conditions are optimized. The diaphragm 37 is driven by an iris motor 50 and adjusts the exposure by adjusting the size of the opening that opens the photographing optical axis. The shutter 39 is driven by a shutter motor 53. The shutter motor 53 moves the shutter 39 between a closed position where light to the CCD 40 is blocked and an open position where the CCD 40 is exposed to expose the CCD 40 for a predetermined time.

  These motors 47, 49, 50 and 53 are stepping motors, and their operations are controlled by drive pulses transmitted from a motor driver 57 connected to the CPU 55. When the shutter button 35 is half-pressed during the shooting mode, the focus lens 45 and the diaphragm 37 are driven to adjust the focal length and exposure to perform the shooting preparation process. In the shooting preparation process, strobe charging is performed according to the subject illuminance. When the shutter button 35 is fully pressed in this state, the actual photographing process is performed, the shutter 39 is driven, and the flash light emitting unit 16 emits light when the flash is charged.

  As is well known, the CCD 40 is provided with a plurality of light receiving elements that accumulate subject light as electric charges, and acquires the electric charges accumulated in the respective light receiving elements as imaging signals. The CCD 40 acquires an imaging signal as a through image with a reduced number of pixels when the digital camera 10 is set in the imaging mode, and acquires an imaging signal as a main image when the shutter button 35 is fully pressed during the imaging mode. .

  The imaging signal acquired by the CCD 40 is transmitted by the analog signal processing circuit 59. The analog signal processing circuit 59 is provided with a correlated double sampling circuit (CDS) and an amplifier (AMP) A / D converter (A / D) (not shown). Are amplified, converted to digital image data, and output to the digital signal processing circuit 60.

  The digital signal processing circuit 60 performs various types of image processing such as gradation conversion, white balance correction, and γ correction processing on the input image data. The image data acquired as a through image is displayed on the LCD 27, and the image data acquired as the main image is subjected to image compression in a predetermined compression format (for example, JPEG format), and then passed through the media controller 63. To the memory card 17.

  Each unit of the digital camera 10 is controlled centrally by the CPU 55. The CPU 55 controls driving of each connected unit in accordance with an operation signal input from the operation unit 25 and a shutter drive signal input from the shutter button 35. The CPU 55 is connected to the battery 20 and operates by receiving power supplied through the constant voltage circuit 65. In addition, the CPU 55 supplies the power supplied from the battery 20 to each part of the digital camera 10 and drives each part.

  The CPU 55 is provided with a power supply voltage monitoring unit 67 and measures the terminal voltage (power supply voltage) of the battery 20 in order to estimate the remaining amount of the battery 20. The measurement of the power supply voltage is started when the digital camera 10 is turned on. The power supply voltage monitoring unit 67 is provided with a ROM 69, and a warning voltage value Va, which is a voltage value in which it is preferable to charge or replace the battery 20, and a minimum that can guarantee the operation of each unit of the digital camera 10. Is stored as a limit voltage value Vb (see FIG. 5).

  The power supply voltage monitoring unit 67 refers to the ROM 69 and displays a warning message on the LCD 27 when the measured power supply voltage value falls below the warning voltage value Va. As the warning message, for example, as shown in FIG. 4 (A), a battery remaining low warning or a message prompting charging of the battery is used. Further, the power supply voltage monitoring unit 67 performs a power supply shut-off process in order to prevent malfunction when the measured power supply voltage value falls below the limit voltage value Vb. In the power shut-off process, for example, after a notification message as shown in FIG. 4B is displayed on the LCD 27, each part of the digital camera 10 is safely stopped and then the power is turned off.

  The measurement of the power supply voltage is normally continuously performed while the power of the digital camera 10 is turned on. However, the power supply voltage value fluctuates depending on the operation status of each part and may temporarily decrease. In the actual photographing process performed when the shutter button 35 is fully pressed, each component of the digital camera 10 is operated, so that a drop in the power supply voltage value is remarkable, especially when the shutter 39 is driven. It was found that the voltage value decreased.

  For this reason, during driving of the shutter 39, the power supply voltage value may temporarily fall below the warning voltage value or the limit voltage value. In this case, although the remaining amount of the battery 20 is still sufficient, a warning message is displayed or a power shutdown process is performed. In order to prevent such a problem, the digital camera 10 determines that when the shutter button 35 is fully pressed, the battery 20 has a remaining amount necessary for execution of the main photographing process. The measurement of the power supply voltage during driving of the shutter 39 is interrupted.

  FIG. 5 is an explanatory diagram showing the timing of interruption of measurement of the power supply voltage by the power supply voltage monitoring unit 67. When the digital camera 10 is turned on, the power supply voltage monitoring unit 67 starts measuring the power supply voltage. A shutter drive signal is input to the power supply voltage monitoring unit 67. When the shutter button 35 is fully pressed, this is detected, and the power supply voltage value at this time is examined. If the power supply voltage value exceeds the warning voltage value Va, it is determined that the battery 20 has a remaining amount necessary for execution of the main photographing process, and the power supply voltage is measured before the shutter 39 is driven. Interrupt. The measurement of the power supply voltage is resumed after the driving of the shutter 39 is completed.

  Hereinafter, the operation of the first embodiment of the present invention having the above configuration will be described with reference to the flowchart shown in FIG. When the power of the digital camera 10 is turned on, the power supply voltage monitoring unit 67 starts measuring the power supply voltage. When the power supply voltage value drops below the warning voltage value Va and the battery 20 is preferably charged or replaced, a warning message is displayed on the LCD 27 (see FIG. 4A). Further, when the power supply voltage value decreases and falls below the limit voltage value Vb and the operation of each part of the digital camera 10 cannot be guaranteed, a notification message is displayed on the LCD 27, and then the power supply is turned off (FIG. 4B )reference).

  Further, the digital camera 10 checks the power supply voltage value when the full press of the shutter button 35 is detected. If the power supply voltage value at this time exceeds the warning voltage value Va and it is determined that the battery 20 has a remaining amount necessary for execution of the main photographing process, the power supply voltage during driving of the shutter 39 is determined. Interrupts the value measurement.

  As described above, when it is determined that the remaining amount of the battery 20 estimated from the power supply voltage value does not hinder the execution of the main photographing process, the digital camera 10 measures the power supply voltage while the shutter 39 is being driven. Since the operation is interrupted, there is no possibility that a warning message or a power-off process is performed due to a temporary decrease in the power supply voltage value accompanying the driving of the shutter 39.

  In this example, when the power supply voltage value exceeds the warning voltage value, it is determined that the battery has a remaining amount necessary for execution of the main photographing process. However, the present invention is not limited to this. is not. A new voltage value is set separately from the warning voltage value, and when the power supply voltage value exceeds the newly set voltage value, it is determined that the battery has sufficient remaining capacity for executing the main photographing process. You may do it. In addition, when the power supply voltage value exceeds the warning voltage value, the measurement of the power supply voltage while driving the shutter is interrupted, but the power supply voltage measurement is performed while the shutter is driving regardless of the power supply voltage value. May be interrupted.

  Hereinafter, Example 2 of the present invention will be described. In the following embodiments, the same members as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In the digital camera 70 shown in FIG. 7, the CPU 55 is provided with a power supply voltage monitoring unit 73 to measure the power supply voltage. The power supply voltage monitoring unit 73 starts measurement when the power of the digital camera 70 is turned on, and continuously performs measurement until the power is turned off.

  The power supply voltage monitoring unit 73 is provided with a ROM 69 and stores a warning voltage value Va and a limit voltage value Vb. The power supply voltage monitoring unit 73 refers to the ROM 69 and displays a warning message on the LCD 27 when the measured power supply voltage value falls below the warning voltage value Va (see FIG. 4A). When the measured power supply voltage value falls below the limit voltage value Vb, a notification message is displayed on the LCD 27, and then the power supply is turned off (see FIG. 4B).

  As described above, during the driving of the shutter 39, the power supply voltage value temporarily decreases, and the power supply cutoff process may be performed below the limit voltage value. When such a problem occurs, the digital camera 70 assumes that the power supply voltage value drop due to the shutter drive is almost the same every time, so that the power supply voltage value will be the limit voltage value during the future shutter drive. It is predicted whether or not the power is cut off, and reoccurrence of the power cut-off process during the shutter driving is prevented.

  The power supply voltage monitoring unit 73 is provided with an EEPROM 75. The EEPROM 75 is provided with two storage areas, a first area 76 and a second area 77. In the first area 76, the power supply voltage value Vc at the time when the shutter button 35 is fully pressed is written. On the other hand, in the second region 77, when the power cut-off process is performed while the shutter 39 is driven, the voltage value stored in the first region 76 at this time is the shutter drive prohibition. It is written as a voltage value Vd.

  After recording the voltage value in the EEPROM 75, the power supply voltage monitoring unit 73 compares the measured power supply voltage value with the shutter drive prohibition voltage value Vd, and the measured power supply voltage value is lower than the voltage value Vd. In this case, if shutter driving is performed in the future, it is predicted that the power supply voltage value will fall below the limit voltage value Vb during shutter driving as before, and the driving of the shutter 39 is prohibited after this prediction. Further, an explanatory message for notifying this is displayed on the LCD 27. As the explanation message, for example, as shown in FIG. 8, a message indicating that shutter drive is prohibited, a message prompting charging of the battery, or the like is used. Further, the notification by the explanation message is also performed when the shutter button 35 is fully pressed in a state where the driving of the shutter 39 is prohibited.

  Hereinafter, the operation of the second embodiment of the present invention having the above-described configuration will be described with reference to the flowchart shown in FIG. When the power of the digital camera 70 is turned on, the power supply voltage monitoring unit 73 starts measuring the power supply voltage value. When the power supply voltage value decreases and falls below the warning voltage value Va, a warning message is displayed on the LCD 27 (see FIG. 4A). Further, when the power supply voltage value decreases and falls below the limit voltage value Vb, a notification message is displayed on the LCD 27, and then the power supply is turned off (see FIG. 4B).

  In addition, the digital camera 70 stores the power supply voltage value Vc when the shutter button 35 is fully pressed in the first area 76, and when the power shutdown process is performed during execution of the main photographing process, it is stored in the first area at this time. Is stored in the second region 77 as the shutter drive inhibition voltage value Vd. Then, after the voltage value is recorded in the EEPROM 75, the digital camera 70 determines that the power supply voltage value during the shutter drive will be reduced if the measured power supply voltage value falls below the shutter drive inhibition voltage value Vd and the shutter drive is performed in the future. It is predicted that the voltage will fall below the limit voltage value Vb, and the subsequent drive of the shutter 39 is prohibited. Further, an explanatory message is displayed on the LCD 27 (see FIG. 8) to notify that effect. Furthermore, an explanation message is also displayed when the shutter button 35 is fully pressed while the driving of the shutter 39 is prohibited.

  Thus, when the shutter 39 is driven when the measured power supply voltage value is lower than the voltage value Vd that has been subjected to the power shutoff process during the previous shutter drive, the digital camera 70 again performs the power shutoff process during the shutter drive. Is expected to occur. In such a case, since the shutter drive is prohibited, it is possible to prevent a problem such as a sudden power interruption process being performed during the shutter drive. Further, when it is predicted that the power shut-off process will be performed during the shutter driving in the future, the fact is notified before the shutter driving, so that measures such as charging the battery in advance can be taken.

  In the second embodiment, the prevention of the recurrence of the problem that the power-off process is suddenly performed during the shutter driving is described as an example. However, the recurrence prevention of the problem that the warning is suddenly performed during the driving of the shutter is described. You may make it do. In this case, when the warning voltage value Va falls below the shutter driving, the voltage value stored in the first area 76 at this time is stored as the preliminary warning voltage value. If the measured power supply voltage value is lower than the preliminary warning voltage value, it is predicted that a warning will be given during the shutter driving if the shutter driving is performed in the future, and a warning is given in advance before the shutter driving. do it.

  Hereinafter, Example 3 will be described. In the digital camera 80 shown in FIG. 10, the CPU 55 is provided with a power supply voltage monitoring unit 83 to measure the power supply voltage. The power supply voltage monitoring unit 83 starts measurement when the power of the digital camera 80 is turned on, and continuously performs measurement until the power is turned off.

  The power supply voltage monitoring unit 83 is provided with a ROM 69 and stores a warning voltage value Va and a limit voltage value Vb. The power supply voltage monitoring unit 83 refers to the ROM 69 and displays a warning message on the LCD 27 when the measured power supply voltage value falls below the warning voltage value Va (see FIG. 4A). When the measured power supply voltage value falls below the limit voltage value Vb, a notification message is displayed on the LCD 27, and then the power supply is turned off (see FIG. 4B).

  As described above, when the shutter 39 is driven, the power supply voltage value temporarily decreases and falls below the limit voltage value, which causes a problem. In order to prevent such a problem, the digital camera 80 assumes that the power supply voltage value drop due to shutter driving can be considered to be almost the same every time, so that the power supply voltage value will be the limit voltage value during the future shutter driving. The power cutoff processing during the shutter driving is prevented.

  The power supply voltage monitoring unit 83 is provided with an EEPROM 85. The EEPROM 85 is provided with three storage areas, a first area 86, a second area 87, and a third area 88. As shown in FIG. 11, the power supply voltage value Vc at the time when the shutter button 35 is fully pressed is written in the first area 86. In the second area 87, the power supply voltage value Ve during driving of the shutter 39 is written. In the third region 88, a differential voltage value Vf obtained by subtracting the voltage value Ve from the voltage value Vc is written. Each voltage value written in the EEPROM 85 is updated every time the shutter 39 is driven.

  After the shutter drive, the power supply voltage monitoring unit 83 obtains a value obtained by subtracting the differential voltage value Vf from the measured power supply voltage value as an estimated value (estimated voltage value Ve ′) of the power supply voltage value during the future shutter drive. Then, when the estimated voltage value Ve ′ is compared with the limit voltage value Vb and the estimated voltage value Ve ′ is lower than the limit voltage value Vb, if the shutter drive is performed in the future, the power It is predicted that the voltage value will fall below the limit voltage value Vb, and after this prediction, the driving of the shutter 39 is prohibited. Further, an explanatory message for notifying this is displayed on the LCD 27 (see FIG. 8). Further, the notification by the explanation message is also performed when the shutter button 35 is fully pressed in a state where the driving of the shutter 39 is prohibited.

  Hereinafter, the operation of the third embodiment of the present invention having the above-described configuration will be described with reference to the flowchart shown in FIG. When the power of the digital camera 80 is turned on, the power supply voltage monitoring unit 83 starts measuring the power supply voltage value. When the power supply voltage value decreases and falls below the warning voltage value Va, a warning message is displayed on the LCD 27 (see FIG. 4A). Further, when the power supply voltage value decreases and falls below the limit voltage value Vb, a notification message is displayed on the LCD 27, and then the power supply is turned off (see FIG. 4B).

  In addition, when the shutter button 35 is fully pressed, the digital camera 80 supplies the power supply voltage value Vc when the shutter button 35 is fully pressed to the first area 86 and the power supply voltage value Ve during driving of the shutter 39 to the second area. In 87, the differential voltage value Vf obtained by subtracting the voltage value Ve from the voltage value Vc is stored in the third region 88, respectively.

  After the shutter driving, the digital camera 80 compares the estimated voltage value Ve ′ obtained by subtracting the differential voltage value Vf from the measured power supply voltage value and the limit voltage value Vb. If the estimated voltage value Ve ′ is lower than the limit voltage value Vb, it is predicted that the power supply voltage value will be lower than the limit voltage value Vb during shutter drive in the future when shutter driving is performed. The drive of the shutter 39 is prohibited. Further, an explanatory message for notifying this is displayed on the LCD 27 (see FIG. 8). Further, the notification by the explanation message is also performed when the shutter button 35 is fully pressed in a state where the driving of the shutter 39 is prohibited.

  As described above, the digital camera 80 prohibits the shutter drive when it is predicted that the power shut-off process will be performed during the future shutter drive based on the reduction width of the power supply voltage at the time of the shutter drive performed in the past. As a result, it is possible to prevent a problem that the power-off process is suddenly performed while the shutter is being driven. Further, when it is predicted that the power shut-off process will be performed during the shutter driving in the future, the fact is notified before the shutter driving, so that measures such as charging the battery in advance can be taken.

  In the third embodiment, an example of preventing the problem of sudden power-off processing during shutter driving has been described. However, the problem of sudden warning during shutter driving is prevented. May be. In this case, the estimated voltage value Ve ′ and the warning voltage value Va are compared, and if the estimated voltage value Ve ′ is lower than the limit voltage value Va, when the shutter drive is performed in the future, the shutter A warning may be predicted in advance before driving the shutter by predicting that a warning will be given during driving.

  Further, in the third embodiment, the estimated voltage value Ve ′ has been described based on an example in which the estimated voltage value Ve ′ is estimated from the decrease width of the power supply voltage value in the past one-time shutter driving. You may make it estimate from the average value of the fall range of a value.

  Hereinafter, Example 4 will be described. In the digital camera 90 shown in FIG. 13, the CPU 55 is provided with a power supply voltage monitoring unit 93 to measure the power supply voltage. The power supply voltage monitoring unit 93 starts measurement when the power of the digital camera 90 is turned on, and continuously performs measurement until the power is turned off.

  The power supply voltage monitoring unit 93 is provided with a ROM 69 and stores a warning voltage value Va and a limit voltage value Vb. As described above, the power supply voltage value varies depending on the operation status of each component of the digital camera 90. The digital camera 90 varies the warning voltage value Va and the limit voltage value Vb based on the variation of the power supply voltage value accompanying the operation of each component, thereby limiting the power supply voltage value during future shutter driving. It is predicted whether or not the voltage value is lower, and a warning during driving the shutter and a power-off process are prevented.

  The power supply voltage monitoring unit 93 is provided with an EEPROM 95 having first to fourth storage areas 96 to 99. As shown in FIG. 14, when the shutter 39 is driven, the power supply voltage during driving of the shutter 39 is displayed in the first region 96 from the power supply voltage value Vg during live view display performed before this shutter drive. The differential voltage value (Vg−Ve) obtained by subtracting the value Ve is stored.

  Similarly, the second area 97 stores a differential voltage value (Vh−Ve) obtained by subtracting the voltage value Ve from the power supply voltage value Vh during strobe charging performed before the shutter driving. The third area 98 stores a differential voltage value (Vi−Ve) obtained by subtracting the voltage value Ve from the power supply voltage value Vi during driving of the zoom lens 43 performed before the shutter driving. The fourth area 99 stores a differential voltage value (Vj−Ve) obtained by subtracting the voltage value Ve from the power supply voltage value Vj during driving of the focus lens 45 performed before the shutter driving.

  When the power source voltage monitoring unit 93 records each differential voltage value in the EEPROM 95, the differential voltage value (Vg−Ve) is added to the warning voltage value Va and the limit voltage value Vb during the subsequent through image display. . Similarly, the differential voltage value (Vh−Ve) is obtained during strobe charging, the differential voltage value (Vi−Ve) is driven while the zoom lens 43 is being driven, and the differential voltage value (Vj−Ve) while the focus lens 45 is being driven. Is added to the warning voltage value Va and the limit voltage value Vb. Thus, the warning voltage value Va and the limit voltage value Vb vary depending on the operating state of the digital camera 90 (hereinafter, the changed warning voltage value and limit voltage value are referred to as the warning voltage value Va ′ and the limit voltage value Vb ′, respectively). Called).

  The power supply voltage monitoring unit 93 compares the measured power supply voltage value with the warning voltage value Va ′. When the measured power supply voltage value falls below the warning voltage value Va ′, when the shutter drive is performed in the future, the power supply voltage value is predicted to fall below the warning voltage value Va during the shutter drive. A warning message is displayed on the LCD 27 (see FIG. 4A).

  Similarly, the power supply voltage monitoring unit 93 compares the measured power supply voltage value with the limit voltage value Vb ′. If the measured power supply voltage value falls below the limit voltage value Vb ′, it is predicted that the power supply voltage value will fall below the limit voltage value Vb during the shutter drive when the shutter drive is performed in the future. After the notification message is displayed on the LCD 27, the power is turned off (see FIG. 4B).

  The operation of the digital camera 90 configured as described above will be described with reference to the flowchart shown in FIG. When the power of the digital camera 90 is turned on, the power supply voltage monitoring unit 93 starts measuring the power supply voltage.

  When the shutter 39 is driven, the power supply voltage value during driving of the shutter is subtracted from the power supply voltage value during driving of the zoom lens 43 and the focus lens 45 during live view display, strobe charging performed before the shutter driving. Thus, a differential voltage value for each operation is calculated. Then, when each operation is subsequently executed, the corresponding differential voltage value is added to the warning voltage value Va and the limit voltage value Vb. As a result, a warning voltage value Va ′ and a limit voltage value Vb ′ that vary according to the operation are obtained (see FIG. 14).

  Subsequently, the measured power supply voltage value is compared with the warning voltage value Va ′. If the measured power supply voltage value falls below the warning voltage value Va ′ and the shutter drive is performed in the future, the power supply voltage value is predicted to fall below the warning voltage value Va during the shutter drive. A warning message is displayed on the LCD 27 (see FIG. 4A). Next, the measured power supply voltage value is compared with the limit voltage value Vb ′. If the measured power supply voltage value falls below the limit voltage value Vb ′ and the shutter drive is performed in the future, the power supply voltage value is predicted to fall below the limit voltage value Vb during the shutter drive. After the notification message is displayed on the LCD 27, the power is turned off (see FIG. 4B).

  The digital camera 90 fluctuates the warning voltage value and the limit voltage value based on the fluctuation of the power supply voltage value during each operation performed in the past, and when the shutter is driven in the future, the warning or power cut-off process is performed during the shutter drive driving. When it is predicted that a warning will be made, a warning or power-off process is performed before the shutter is driven. Thereby, not only can the warning during the shutter drive and the power cut-off process be prevented, but the photographer can know the decrease in the remaining amount of the power at an early stage and can take measures such as charging the battery.

  In the fourth embodiment, the case where the measured power supply voltage value is lower than the limit voltage value after the fluctuation has been described as an example in which the power shutdown process is performed at that time. However, the power shutdown process is performed at this time. Instead, the subsequent shutter drive may be prohibited. In this case, when shutter driving is prohibited, an explanatory message notifying that is displayed on the LCD.

  As described above, in the first to fourth embodiments, the example of preventing the warning during the shutter driving and the problem of the power shut-off process in the main photographing process has been described. However, the present invention is not limited to this. As the main photographing process, various operations are performed in addition to the shutter drive. Therefore, by applying the present invention to these various operations, a warning during the execution of these various operations and a power-off process are prevented. It is also possible. In addition, according to the present invention, it is possible to prevent a warning or a power-off process during the shooting preparation process.

It is an external view of the front side of a digital camera. It is an external view of the back side of a digital camera. It is a block diagram showing the structure of a digital camera. It is explanatory drawing showing a mode that the warning message and the notification message were displayed. It is explanatory drawing showing the fluctuation | variation of the electric source voltage by shutter drive. It is a flowchart showing the measurement procedure of a power supply voltage. It is a block diagram showing the structure of a digital camera. It is explanatory drawing showing a mode that the explanatory message was displayed. It is a flowchart showing the recurrence prevention procedure of the power-off process during shutter driving. It is a block diagram showing the structure of a digital camera. It is explanatory drawing showing the fluctuation | variation of the electric source voltage by shutter drive. It is a flowchart showing the prevention procedure of the power-supply-cutoff process during shutter drive. It is a block diagram showing the structure of a digital camera. It is explanatory drawing showing the fluctuation | variation of a warning voltage value and a limit voltage value. It is a flowchart showing the fluctuation | variation procedure of a warning voltage value or a limit voltage value.

Explanation of symbols

10, 70, 80, 90 Digital camera 13 Shooting lens 20 Battery 27 LCD
29 Zoom lever 33 Power switch 35 Shutter button 37 Aperture 39 Shutter 43 Zoom lens 45 Focus lens 55 CPU
67, 73, 83, 93 Power supply voltage monitor 69 ROM
75, 85, 95 EEPROM

Claims (7)

It is driven by power supplied from a power source, performs a predetermined photographing process in accordance with the operation of the shutter button, picks up a subject image obtained through the photographing lens, and measures power source voltage and measures power source voltage. In a camera comprising a power shut-off means for performing a power shut-off process to stop the supply of power when the power supply voltage value is lower than a preset limit voltage value,
The power supply voltage measurement unit executes the shooting process when it is determined that the power supply voltage value at the time of operating the shutter button is higher than the limit voltage value by a predetermined value or more and the power supply has a remaining amount necessary for executing the shooting process. Interrupt the measurement of the power supply voltage inside,
A camera that prevents a power-off process during execution of a photographing process due to a temporary drop in power supply voltage accompanying the execution of the photographing process. A warning voltage value that is higher than the limit voltage value is set, and when the measured power supply voltage value is lower than the warning voltage value, a warning unit that issues a warning of a drop in the power supply voltage value,
The power supply voltage measurement unit determines that the power supply has a remaining amount necessary for executing the photographing process when the power supply voltage value at the time of operating the shutter button exceeds the warning voltage value. 2. The camera according to claim 1, wherein the measurement of the power supply voltage value is interrupted. It is driven by power supplied from a power source, performs a predetermined photographing process in accordance with the operation of the shutter button, picks up a subject image obtained through the photographing lens, and measures power source voltage measuring means for measuring the power source voltage. In a camera comprising a power shut-off means for performing a power shut-off process to stop the supply of power when the power supply voltage value is lower than a preset limit voltage value,
Based on the fluctuations in the power supply voltage value associated with the execution of the imaging process performed in the past, it is predicted that the power supply voltage value will fall below the limit voltage value during the next imaging process execution. In this case, prohibition means for prohibiting execution of the next shooting process,
Notification means for performing notification of power supply voltage value reduction and notification of imaging processing prohibition when the prohibiting means predicts that the power supply voltage value is lower than the limit voltage value during execution of the next imaging processing; A camera characterized by providing.   The prohibiting means stores the power supply voltage value before execution of the photographing process as a prohibited voltage value when the power shut-off process is performed during the photographing process, and the power supply voltage value at the predicted time point indicates the prohibited voltage value. 4. The camera according to claim 3, wherein when the value is lower, the power supply voltage value is predicted to be lower than the limit voltage value during a future photographing process.   The prohibiting means stores a differential voltage value obtained by subtracting a power supply voltage value during execution of imaging processing from a power supply voltage value before execution of imaging processing, and a value obtained by subtracting the differential voltage value from the power supply voltage value at the prediction time point, The camera according to claim 3, wherein, when the value is lower than the limit voltage value, the power supply voltage value is predicted to be lower than the limit voltage value during execution of a future photographing process.   The prohibiting means stores a differential voltage value obtained by subtracting a power supply voltage value during execution of shooting processing from a power supply voltage value before execution of shooting processing, and sets the limit voltage value until a future shooting processing is executed. By adding the estimated value, the limit voltage value is changed, and when the power supply voltage value at the prediction time is lower than the limit voltage value after the change, the power supply voltage value is set to the limit during execution of a future photographing process. The camera according to claim 3, wherein the camera is predicted to be lower than the voltage value. Warning means for issuing a warning of a power supply voltage drop when a warning voltage value that is higher than the limit voltage value is set and the power supply voltage value measured by the power supply voltage measurement means is lower than the warning voltage value Prepared,
The warning means predicts whether or not the power supply voltage value falls below the warning voltage value during execution of the next shooting process based on the fluctuation of the power supply voltage value associated with the execution of the shooting process performed in the past, The camera according to claim 3, wherein the warning is performed at a prediction time when it is predicted to fall below.

Images