JP4700865B2 - Recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a power supply unit for using AC power, related to at least one of the mountable recording apparatus with a battery.
[0002]
[Prior art]
An imaging operation of a general digital camera will be described. When the release switch is turned on by pressing the release member and the imaging operation is started, through a well-known photometric operation and focus adjustment, the photographic light flux from the subject passes through the photographic lens and is controlled to an appropriate light amount by the shutter and the diaphragm. Incident on the CCD (sensor). The photographing light beam is photoelectrically converted by the CCD, and an image signal can be obtained by performing predetermined image processing by a signal processing circuit. The image signal is converted into a digital signal via an A / D conversion circuit and temporarily stored in a frame memory which is a volatile memory built in the digital camera body. Thereafter, a well-known data compression process is performed in the compression circuit, and the data is recorded on a removable non-volatile recording medium such as a memory card via a card I / F (interface).
[0003]
Unlike a camera using a silver salt film, a digital device such as a digital camera is equipped with an imaging device such as a CCD as described above, and consumes more power. In recent years, since the performance of the battery (battery) has improved, there is a battery having a small capacity and a large capacity. However, although the performance is improved, the capacity of the battery is finite, and the time for supplying sufficient power to the digital device is limited. Therefore, in consideration of using an AC power supply unit that obtains electric power from a commercial power supply, either a battery or an AC power supply unit can be mounted and used.
[0004]
When a commercial power supply (AC power supply) is used instead of a battery, the power can be used without limitation if there is no trouble unlike the battery. However, when the plug of the commercial power supply device is inadvertently removed from the outlet or when a power failure occurs unexpectedly, the power supply is suddenly cut off (hereinafter referred to as “power supply interruption”). If a power interruption occurs while the digital camera is recording image data on a recording medium such as a memory card, it will not be possible to leave the data being written (hereinafter referred to as recording operation). , There is a possibility of affecting already recorded data. For this reason, a measure to secure a certain voltage until the recording operation is completed by mounting a backup capacitor and delaying the voltage drop can be considered. However, when there is a large amount of data to be stored, such as large-capacity image data, the time required for the recording operation is also large. If the amount of data is large, the voltage drops below the minimum operating voltage before the recording operation is completed. In some cases, the data in the recording medium cannot be left normal. In addition, it is conceivable to increase the size of the backup capacitor as one of the delay means so that more power required for recording time can be stored. However, if the size is increased, the portability is reduced and the cost is increased. End up.
[0005]
Japanese Patent Application Laid-Open No. 11-41534 discloses a technique for ensuring a recording operation time without increasing the size of a backup capacitor even when an instantaneous power interruption occurs when using a commercial power supply. According to Japanese Patent Application Laid-Open No. 11-41534, when using a commercial power supply, the power supply voltage is observed, and when it is detected that the power supply voltage is not supplied to the digital device, the data is immediately stored in the nonvolatile memory, It tries to protect data before power interruption.
[0006]
[Problems to be solved by the invention]
Even when a battery is used as a power source for a digital device such as a digital camera, if the power that can be supplied by the battery is low, data during recording cannot be left, and data that has already been recorded may be affected. .
[0007]
However, unlike the case of using a commercial power supply, it is unlikely that an instantaneous power interruption will occur when a battery is used as the power supply. Therefore, as described in Japanese Patent Application Laid-Open No. 11-41534, a method of storing data in a nonvolatile memory after detecting that a power supply voltage is not supplied to a digital device uses a battery as a power supply. Not applicable in some cases. In addition, when the battery is used, the power supply voltage is lowered due to the voltage drop of the battery, and it is easier to secure the recording operation time than when the commercial power supply is used.
[0008]
The present invention includes a power supply unit for using AC power, even when the voltage supplied from any one of the battery is lowered, an image can be recorded data stored in the memory in a nonvolatile recording medium The purpose is to do so .
[0009]
[Means for Solving the Problems]
A recording apparatus according to the present invention is a recording apparatus to which at least one of a power supply unit for using an AC power source and a battery can be attached, a memory for storing image data, and an image data stored in the memory. A recording unit that performs a first process of recording on a non-volatile recording medium; and a control unit that controls whether or not to stop a second process different from the first process. wherein a case the recording apparatus is mounted, and, when said battery is not mounted on the recording apparatus, the voltage supplied from the power supply unit is rather low than the second voltage, the third voltage If the above is true, the control means does not stop the first process, but stops the second process, and the power supply unit is not attached to the recording apparatus. And, If the serial battery is mounted in the recording apparatus, the voltage supplied from the battery rather lower than the first voltage, when said at third voltage higher, said control means, said first The processing is not stopped, but the second processing is stopped, and when the power supply unit and the battery are attached to the recording apparatus, the voltage supplied from the power supply unit or the battery is the rather low than the first voltage, when said at third voltage higher than said control means is to not stop the first process, so as to stop the second process, the second voltage, the first rather higher than the voltage, the third voltage, said recording means is a voltage capable of performing said first process, said third voltage, said the first voltage and Japanese is lower than said second voltage To.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
1 to 5 are diagrams for explaining an embodiment of the present invention. 1 to 3, the same members are denoted by the same reference numerals.
[0013]
First, the connection between the digital camera body and the power supply device will be described with reference to FIG.
[0014]
Reference numeral 1 denotes a digital camera body, and a mounting portion 1 a for a power supply device is provided at the bottom of the digital camera body 1. Reference numeral 2 denotes an interchangeable photographic lens attached to the digital camera body 1. Reference numeral 3 denotes a release member for starting the photographing operation of the digital camera. When the release member 3 is pressed, known photometry, focus detection operation, imaging operation, and the like are performed. Reference numerals 4, 5, and 6 denote power supply devices that supply power to the digital camera body, and reference numeral 4 denotes a battery. Reference numeral 4a denotes a battery coupler, which includes a rechargeable secondary battery such as a nickel metal hydride battery. An output terminal 4b supplies power to the digital camera body. 5 is an AC power supply unit for using a commercial power supply, 5a is an AC power supply coupler section, and 5b is an output terminal. Reference numerals 5c and 5d are backup capacitors which are accommodated in the coupler unit 5a and accumulate electric charges by a commercial power supply, and are connected to the output terminal 5b. Reference numeral 5e denotes an AC / DC converter, which plays the role of stepping down the AC power source to a DC constant voltage. An AC cable 5f is connected to a commercial power outlet and supplies AC power to the AC / DC converter unit. Reference numeral 5g denotes a cable connecting the AC / DC converter unit 5e and the coupler unit 5a. In this embodiment, since the battery 4 and the AC power supply unit 5 are attached to the same terminal of the digital camera body, the backup capacitors 5c and 5d are provided inside the AC power supply unit 5. As long as the power supply unit 5 is attached to different terminals of the digital camera body, the backup capacitor may be provided in the digital camera body. 6 is a large-capacity battery unit, 6a is a coupler unit, 6b is an output terminal, and 6c is a large-capacity battery storage unit, which can store a larger amount of power than the battery 4. Reference numeral 6d denotes a cable connecting the coupler unit 6a and the large-capacity battery storage unit 6c. Any one of the power supply devices 4, 5, and 6 can be attached to the power supply unit 1a, and power is supplied to the digital camera body via the output terminals 4b, 5b, and 6b of the respective power supplies. Is called.
[0015]
FIG. 2 is a diagram illustrating a state in which the AC power supply unit 5 that is one of the power supply units is mounted on the mounting portion 1 a of the digital camera body 1.
[0016]
FIG. 3 is a block diagram showing a circuit configuration of the digital camera according to the present invention.
[0017]
In the figure, reference numeral 3 denotes a release member also shown in FIG. 1, and when pressed, the switch SW1 is turned on in the first stroke and the switch SW2 is turned on in the second stroke. In the figure, the battery 4 or 6 that is a power supply device and the AC power supply unit 5 are described for the sake of explanation, but in actuality, any one of the power supply devices of any of 4, 5 and 6 is shown. Install and use. The battery here includes both the battery 4 and the large-capacity battery unit 6. Hereinafter, the battery is treated as including either the battery 4 or the large-capacity battery unit 6. Reference numeral 11 denotes a control circuit for controlling the circuits of the entire digital camera, and includes a CPU that manages the entire digital camera, an interface circuit of the CPU, a timing circuit that supplies a clock signal to each circuit, and the like. Reference numeral 12 denotes a display device composed of a liquid crystal monitor, which displays an image captured based on an image signal processed by a signal processing circuit 21 described later. Reference numeral 13 denotes various operation buttons which are input operation members. When the interlocked switch is operated, the control circuit 11 executes processing corresponding to the operation of the switch. Also, shooting information such as shutter speed, aperture value, number of shot frames, number of remaining frames, and the like are displayed as necessary. Reference numeral 14 denotes an LED indicator, which displays a mark indicating that the power supply voltage is insufficient by lighting or blinking according to a determination result of a voltage comparison circuit 17 described later. A power determination circuit 15 determines whether the power supply device mounted on the digital camera body 1 is the AC power supply unit 5 or the battery 4 or 6. A power control circuit 16 stabilizes the input voltage and controls the supply of power to the display device 12 and other circuits, which are loads in the digital camera. Reference numeral 17 denotes a voltage comparison circuit that monitors (detects) voltages supplied from various power supply devices, compares the voltage with a reference voltage that is a predetermined value set in advance for each type of power supply device, and compares the result with the control circuit. 11 is output.
[0018]
Next, image recording in this block diagram will be described. When the release member 3 is operated and SW1 and SW2 are turned on to start the imaging operation, the photographing light flux from the subject passes through the photographing lens 18 and is adjusted to an appropriate light amount by the shutter and the diaphragm 19. The photographing light flux adjusted to an appropriate amount of light enters a CCD (sensor) 20 that is an image pickup device and is photoelectrically converted, and a signal processing circuit 21 performs processing such as γ correction to form an image signal. The image signal is converted into a digital signal by the A / D conversion circuit 22 and temporarily stored in the frame memory 23. Then, after a known data compression process is performed by the compression circuit 24, the data is recorded on the memory card 26 via a card I / F (interface) 25.
[0019]
FIG. 4 is a diagram showing the relationship between the power supply voltage and the recording operation time.
[0020]
In the figure, the vertical axis represents power supply voltages of various power supply devices, and the horizontal axis represents time. In the figure, Vbat indicates the power supply voltage of the battery, and Vac indicates the power supply voltage of the AC power supply unit. The battery power supply voltage Vbat gradually decreases with time, and the battery voltage gradually decreases with time. On the other hand, since the power supply voltage Vac of the AC power supply unit uses a commercial power supply, the output voltage from the AC / DC converter is substantially constant because the voltage waveform always repeats the same pattern if normal power supply is performed. Value.
[0021]
Vth1 is a first reference voltage, which is a reference voltage set when a battery is used as the power source of the digital camera. Vth2 is a second reference voltage, which is a reference voltage set when a commercial power supply is used as the power supply of the digital camera. The second reference voltage Vth2 is set higher than the first reference voltage Vth1. Vmin is a minimum operation guarantee voltage, and is a voltage that can at least guarantee a predetermined operation requiring an emergency.
[0022]
t1 is a time required for the recording operation when the battery is used, and is a time required for recording data in the external memory. t2 is the time required for the recording operation when using the commercial power supply, and is the time required for recording data in the external memory.
[0023]
First, a case where a commercial power source is used as a power source will be described.
[0024]
Ts is the timing of instantaneous power interruption. An instantaneous power interruption occurs when the AC power supply unit cable 5f is suddenly disconnected from a commercial power outlet or when a sudden power failure occurs. The power supply voltage begins to drop at a stroke from the momentary power interruption Ts. An instantaneous interruption is detected at the time Tc when the power supply voltage drops to the second reference voltage Vth2, and the digital camera enters the emergency operation mode, and all operations other than the recording operation are prohibited. Since the capacitors 5a and 5b for backup are mounted on the coupler unit 5a of the AC power supply unit 5 and the electric charge accumulated in the capacitors can be used as electric power, the minimum operation guarantee voltage Vmin is detected after the instantaneous interruption is detected. It takes a voltage drop time t3 until it reaches.
[0025]
If the second reference voltage Vth2 is set so that the time t3 is longer than the recording operation required time t2, even if a momentary interruption occurs during the data recording operation or at the start of the recording operation, the recording at this time When the required operation time t2 has elapsed, the power supply voltage does not drop to the minimum operation guarantee voltage Vmin of the digital camera. Therefore, the recording operation can be guaranteed.
[0026]
On the other hand, the case where a battery is used as a power source will be described. When using batteries, there is no instantaneous interruption like when using commercial power. However, the power supply voltage of the battery drops very slowly. When the voltage drops to the first reference voltage Vth1, the control circuit 11 sets the digital camera to the emergency operation mode, and all operations other than the recording operation are prohibited. Even if the voltage of the battery falls below the first reference voltage Vth1, the voltage necessary for performing the recording operation is secured, and the voltage reaches the minimum operation guarantee voltage Vmin of the digital camera before the recording operation time t1 elapses. There is no descent. Therefore, the recording operation can be guaranteed.
[0027]
In the present embodiment, the relationship between the first reference voltage Vth1 and the second reference voltage Vth2 is as follows.
[0028]
Vth1 <Vth2 (1)
The reason is described below.
[0029]
When the power supply voltage is extremely lowered and becomes lower than the minimum operation guarantee voltage Vmin, a malfunction occurs. Not only does the operation become unstable, but there is also a risk of being out of control. Therefore, before the power supply voltage drops to the minimum operation guarantee voltage Vmin, the prohibition voltage level must be set to prohibit or restrict the operation.
[0030]
By the way, when using a battery as a power source, I want to use the same battery as long as possible without leaving any capacity. Therefore, the forbidden voltage level may be set as low as possible within a range in which the required recording operation time t1 can be secured within the minimum operation guarantee voltage Vmin. The prohibited voltage level at this time is the reference voltage Vth1.
[0031]
On the other hand, when a commercial power source is used as a power source, a backup capacitor is connected to the output terminal side of the power source in consideration of momentary interruption. The charge Q accumulated in the capacitor is generally expressed by the following equation.
[0032]
Q = CV (2)
(Q: electric charge, C: electrostatic capacity, V: voltage)
In order to guarantee the operation at the moment of interruption, the more charge stored in the backup capacitor, the safer. Therefore, it is preferable that the Q value in the equation (2) is large. That is, the electrostatic capacity C is increased or the voltage V is set higher. However, when the electrostatic capacity C is increased, the capacitor itself becomes larger and the power supply device becomes larger. In order to prevent an increase in the size of the power supply device, the voltage V may be set high without increasing the capacitance C. Since there is no voltage drop when using a commercial power supply unlike when using a battery, the forbidden voltage level, that is, the second reference voltage Vth2 can be set high. The charge accumulated in the backup capacitor at the time of the second reference voltage Vth2 is Qth2,
Qth2 = C · Vth2 (3)
It can be expressed as
[0033]
Therefore, a charge Qth2 that can maintain a voltage higher than the minimum operation guarantee voltage Vmin even after the recording operation required time t2 elapses is obtained in advance, and the second reference voltage Vth2 is obtained based on the obtained value of Qth2. You only have to set it.
[0034]
That is, even if the recording operation is started at the same time as the instantaneous interruption detection Tc, Vth2 may be set so that the recording operation required time t2 is shorter than the time t3 required for the voltage drop to the minimum operation guarantee voltage Vmin. .
[0035]
Next, a control flow of the digital camera shown in FIGS. 1 to 3 will be described with reference to FIG.
[0036]
In step # 1, when the main power supply is turned on, the digital camera enters an operating state.
[0037]
In step # 2, the control circuit 11 initializes flags and control variables.
[0038]
In step # 3, it is determined whether the power supply device attached to the digital camera body 1 by the power supply determination circuit 15 is an AC power supply unit or a battery (that is, the battery is used as a power supply, or a commercial power supply is used as a power supply). To determine whether to do so. If the attached power supply device is a battery, the process proceeds to step # 4, and conversely if it is an AC power supply unit, the process proceeds to step # 5.
[0039]
In step # 4, since the attached power supply device is a battery, the CPU sets the first reference voltage in the voltage comparison circuit, and proceeds to step # 6.
[0040]
In step # 5, since the attached power supply device is an AC power supply unit, the CPU sets the second reference voltage in the voltage comparison circuit, and proceeds to step # 6.
[0041]
In step # 6, the voltage comparison circuit 17 determines the power supply voltage. The determination of the power supply voltage is compared with the reference voltage (first or second) already set in the previous step. If the power supply voltage is lower than the reference voltage, it is determined as NG and the process proceeds to step # 7. If the power supply voltage is higher than the reference voltage, it is determined as OK and the process proceeds to step # 8.
[0042]
In step # 7, a mark indicating that the power supply voltage is insufficient is blinked (or lit) by the indicator 14, or a warning indicating that the power supply voltage is insufficient is given by the display device 12, and then the power is turned off and step # 1 is performed. Return to.
[0043]
In step # 8, the subject image currently captured by the display device 12 or shooting information is displayed.
[0044]
In step # 9, if it is detected that SW1 is turned on by half-pressing (first stroke) of release member 3, the process proceeds to step # 10. If it is not detected that SW1 is turned on, the process returns to step # 1.
[0045]
In step # 10, a known photometric operation and focus detection operation are performed, and the photographing lens 18 is driven to adjust the focus.
[0046]
In step # 11, if it is detected that the release member 3 is fully pressed (second stroke) and SW2 is turned on, the process proceeds to step # 12. If SW2 is not turned on, the process returns to step # 10 and the photometry operation and focus detection operation are performed again. I do.
[0047]
In step # 12, signal accumulation in the CCD, CCD output signal processing, A / D conversion, and the like are performed as a series of imaging operations.
[0048]
In step # 13, the image data obtained by the imaging operation in step # 12 is temporarily stored in the frame memory 23.
[0049]
In step # 14, compression processing of image data temporarily stored in the frame memory 23 and data writing (recording operation) to the memory card 26 are started.
[0050]
In step # 15, the voltage comparison circuit 17 checks the power supply voltage. In the case where the power supply device is a battery, if the power supply voltage is higher than the first reference voltage based on the detection result of the voltage comparison circuit 17, it is determined to be OK, and the process proceeds to step # 16. Determine and proceed to step # 17. When the power supply device is an AC power supply unit (when using commercial power), if the power supply voltage is higher than the second reference voltage, which is higher than the detection result, it is determined OK and the process proceeds to step # 16. If it is lower, it is judged as NG and the process proceeds to step # 17. Here, as described above, the second reference voltage is set to a value higher than the first reference voltage.
[0051]
In step # 16, display of the image and imaging data obtained by imaging on the display device 12 and reception of the input operation member 13 are continuously performed, and the process proceeds to step # 18.
[0052]
In step # 17, the power supply control circuit 16 stops the power supply to the display device 12, immediately stops the display of the display device 12, prohibits the reception of the input operation member 13, and proceeds to step # 18. However, at this time, only the recording operation is continued.
[0053]
In step # 18, it is determined whether or not the recording operation is completed. If the recording operation is continuing, it is determined that the recording operation is incomplete and the process returns to step # 15. However, if the recording operation is completed, it is determined that the recording operation is completed, and the process proceeds to step # 19.
[0054]
In this way, by setting the prohibited voltage level when using a battery to be lower than the prohibited voltage level when using a commercial power supply, the power supply voltage during the recording operation can be secured both when using the battery and when using the commercial power supply, and The electric charge stored in the battery can be used without wasting it.
[0055]
In the above embodiment, the case where a power supply interruption or a voltage drop occurs during the recording operation of image data or the like from the frame memory to a recording medium such as a memory card has been described. It is not limited. Even when the digital camera is not performing the recording operation to the external recording medium, the recording operation to the external recording medium may be started when the power supply voltage drops and reaches the prohibited voltage level. In this case, even if the photographer does not perform an operation for the recording operation, it is possible to reliably record only the image data captured up to that time to the external recording medium, and the captured image data is not wasted. . However, in this case, in the above embodiment, the power supply voltage is compared with the first or second reference voltage after the recording operation is started, whereas the power supply voltage and the reference voltage are periodically compared separately from the shooting control flow. Control.
[0056]
In the above embodiment, the digital camera capable of mounting either the AC power supply unit or the battery has been described. However, both power supplies may be mounted at once. When both power sources are mounted, power can be supplied by a battery even if an AC power source is interrupted. Therefore, it is only necessary to compare the first reference voltage and the power source voltage in the above embodiment. In this case, the power supply determination circuit determines whether only the AC power supply unit is installed or the battery is installed, and the voltage comparison circuit sets the second reference voltage when only the AC power supply unit is installed. When the battery is attached, the first reference voltage is set regardless of the attachment of the AC power supply unit.
[0057]
In the above embodiment, the embodiment applied to a digital camera as a digital device has been described. Needless to say, data is temporarily stored in a volatile storage medium such as a frame memory, and then stored in a nonvolatile storage medium. It goes without saying that the present invention is applicable to any apparatus having a function of recording the data.
[0058]
【The invention's effect】
According to the present invention, the image data stored in the memory is stored in the nonvolatile recording medium even when the voltage supplied from any one of the power supply unit for using the AC power supply and the battery is lowered. Can be recorded .
[Brief description of the drawings]
FIG. 1 is a diagram showing a digital camera body and a plurality of power supply devices in this embodiment.
FIG. 2 is a diagram showing a state in which a digital camera body and a commercial power supply device are connected in the present embodiment.
FIG. 3 is a block diagram illustrating a circuit configuration of a digital camera according to the present embodiment.
FIG. 4 is a diagram illustrating a relationship between a power supply voltage of a digital camera and a recording operation time in the present embodiment.
FIG. 5 is a diagram showing a processing flow of a control circuit of the digital camera in the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Digital camera main body 1a Mounting part 2 Shooting lens 3 Release member 4 Battery 5 AC power supply unit 5a AC power supply coupler part 5b Output terminal 5c, 5d Backup capacitor 5e AC / DC converter 5f AC cable 5g Cable 6 Large capacity battery unit 6a Coupler part 6b Output terminal 6c Large capacity battery compartment 6d Cable

Claims (4)

A recording apparatus to which at least one of a power supply unit for using an AC power source and a battery can be attached,
A memory for storing image data;
Recording means for performing a first process of recording image data stored in the memory on a nonvolatile recording medium;
Control means for controlling whether or not to stop a second process different from the first process,
It said power supply unit is the case is mounted on the recording apparatus, and, when said battery is not mounted on the recording apparatus, the voltage supplied from the power supply unit is rather low than the second voltage, When the voltage is equal to or higher than the third voltage , the control means does not stop the first process, but stops the second process,
Said power supply unit is the case is not mounted on the recording apparatus, and, when said battery is mounted on the recording apparatus, the voltage supplied from the battery rather lower than the first voltage, the When the voltage is equal to or higher than the third voltage , the control means does not stop the first process, but stops the second process,
Wherein when the power supply unit and said battery is mounted in the recording apparatus, the power supply unit or the voltage supplied from the battery rather lower than the first voltage, when said at third voltage or more, The control means does not stop the first process, but stops the second process,
It said second voltage is rather high than the first voltage,
The third voltage is a voltage at which the recording unit can perform the first processing,
The recording apparatus according to claim 1, wherein the third voltage is lower than the first voltage and the second voltage . The first voltage is a voltage that is set based on a time for the recording unit to perform the first processing when the recording apparatus is supplied with power from the battery;
The second voltage is a voltage set based on a time for the recording unit to perform the first process when the recording apparatus is supplied with power from the power supply unit. Item 2. The recording device according to Item 1. The second process, according to claim 1, characterized in that it comprises inputs and processes for accepting from the operating means for operating the recording apparatus, and a processing for displaying the image data on the display unit Or the recording apparatus of 2.   The recording apparatus according to claim 1, wherein the nonvolatile recording medium is a recording medium that is removable from the recording apparatus.

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