JP3463650B2 - Mobile devices and battery packs used for them - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable device such as a digital camera or a notebook personal computer and a battery pack used for the portable device.

[0002]

2. Description of the Related Art Conventionally, in a portable device using a built-in battery as a main power source, a built-in battery alone may not provide sufficient power. Therefore, a power supply terminal for externally connecting an AC adapter (hereinafter referred to as "power supply terminal"). Battery packs whose terminals are externally connected to a DC jack) are known and commercialized.

Particularly, in a digital camera and a notebook personal computer (hereinafter abbreviated as PC),
A dedicated battery pack and a general-purpose battery pack that supply voltage power using a rechargeable lithium-ion battery have been commercialized.

This type of battery pack has a rechargeable secondary battery and a terminal connectable to a DC jack of an AC adapter (hereinafter, this connection terminal is referred to as a DC plug), and the DC power of the secondary battery is supplied. It is designed to be supplied from a power supply terminal to a mobile device.

On the other hand, the portable equipment is provided with a DC / DC converter as a power supply circuit therein, and the power supply (main power supply) supplied from a built-in battery is converted into a required DC power supply by the DC / DC converter, and the portable equipment is equipped with a DC / DC converter. It is configured to supply various circuits and actuators.

When the battery is driven by the built-in battery, the state of consumption of the built-in battery is regularly monitored, and when the battery voltage drops below a predetermined lower limit voltage that can be driven, the user is prompted to replace the battery. The warning is displayed on.

[0007] In addition, a mobile device usually has a DC jack
When the C plug is connected, the main power supply is designed to be automatically switched from the built-in battery to the AC adapter. Then, since the DC power is stably supplied from the AC adapter, when the main power is switched to the external power supplied from the DC jack, power supply monitoring and warning display such as the case of the power supply by the built-in battery is performed. Control (hereinafter, this control is referred to as battery check control)
Is not done.

[0008]

By the way, in the conventional battery pack, instead of the AC adapter, the DC of the portable device is used.
Since the jack is externally connected and used, when the battery pack is connected to the DC jack, the main power source of the portable device is automatically switched from the built-in battery to the external battery.

However, since the control relating to the power supply in the portable device is switched from the control for the built-in battery to the control for the AC adapter, the battery check control for the battery pack is not performed. Therefore, even if the voltage output from the battery pack falls below a predetermined lower limit voltage that can be driven by the mobile device, the mobile device does not display a warning and suddenly stops driving.

Particularly when the secondary battery built in the battery pack is a lithium ion battery, the battery voltage drops sharply after the power is completely consumed and the device stops. When rewriting, etc., it may develop into a serious problem that the data is destroyed.

If the secondary battery of the battery pack is exhausted, it is possible for the user to replace the battery pack early to avoid the above serious problem. There is no function to display the battery exhaustion state and battery life, and the user has no choice but to estimate the usable time by using the rated capacity of the battery pack as a guide, and the anxiety about the above problems cannot be dispelled.

Further, as a control related to the power source, when the main power source is a battery, in order to reduce the consumption of the battery, a function of automatically stopping the power supply from the power circuit in a certain state (hereinafter referred to as an auto power off function). However, when the battery pack is externally connected, it is treated as if the AC adapter was connected, so there is a problem that the auto power off function does not work for the battery pack.

The present invention has been made in view of the above problems, and when the battery pack is externally connected to the DC jack of the portable device and the portable device is driven by the battery pack, the type and the consumption state of the battery of the battery pack. The present invention provides a portable device and a battery pack used for the portable device, which can perform appropriate power control according to the above.

[0014]

The invention according to claim 1 is
A battery pack used in a mobile device having a power supply terminal for supplying DC power from the outside, wherein the power supply battery and DC power is supplied from the power supply battery to the mobile device via the power supply terminal. When a connection terminal is connected to the power supply terminal, a detection unit that detects that the connection terminal is connected to the power supply terminal, and the connection terminal is connected to the power supply terminal, information about the power supply battery is described above. In order to transmit the voltage to the mobile device, the voltage modulating means for modulating the output voltage of the power supply battery based on the information is provided at least once.

The voltage modulating means may code the information about the power supply voltage and generate a modulation voltage by turning on / off the output voltage of the power supply battery based on the code signal (claim 2). .

The information on the power source battery may include at least the type of battery, the upper limit voltage that can be used, and the lower limit voltage that can be used (claim 3). Further, it is preferable that the apparatus further comprises a remaining capacity detecting means for detecting the remaining capacity of the power supply battery, and the remaining capacity of the battery is included in the information regarding the power supply battery (claim 4).

According to the above configuration, when the connection terminal is connected to the power supply terminal of the portable device and the battery pack is externally connected, the DC power source is supplied from the power supply battery in the battery pack to the portable device through the connection terminal and the power supply terminal. (Main power of mobile device) is supplied. At this time, the output voltage from the power supply battery is modulated and information about the power supply battery such as battery type, usable upper limit voltage, usable lower limit voltage and remaining battery capacity is transmitted to the mobile device at least once. .

For example, a modulation voltage is generated by encoding information about the power supply voltage and turning on / off the output voltage of the power supply battery based on the code signal, and the modulation voltage is transmitted to the portable device.

Therefore, it is possible to perform suitable power supply control by discriminating the information on the power source battery on the portable device side and monitoring the state of the power source based on the discrimination result.

Further, in the invention according to claim 5, the battery pack further comprises display means and display control means for displaying the remaining capacity of the power source battery detected by the remaining capacity detecting means. Is.

According to the above construction, the remaining capacity of the power supply battery is detected, and the detection result is displayed on the display means. This allows the user to easily know the consumption state of the battery of the battery pack.

According to a sixth aspect of the present invention, in the battery pack according to the fifth aspect, the power source battery is a rechargeable secondary battery, and the charging means for the secondary battery and the charging for the secondary battery. The display control means further comprises a counting means for counting the number of times and a non-volatile storage means for storing the number of times of charging the secondary battery counted by the counting means, and the display control means further stores the number of times of charging stored in the storage means. Is displayed on the display means.

It should be noted that the display control means further comprises a determining means for determining whether or not the number of times of charging counted by the counting means exceeds a preset specified number of times. When it exceeds, a warning may be displayed on the display means (claim 7).

According to the above construction, when the secondary battery, which is the power source battery, is exhausted, it can be reused by being charged by the charging means. The number of times of charging is counted, and each time the number of times of charging is stored in the non-volatile memory and displayed on the display means. Further, when the number of times of charging exceeds the preset number of times, a warning of refreshing is further displayed on the display means when the battery life or refreshing is possible. This allows the user to easily estimate the replacement time or the refresh time depending on the life of the battery pack.

The invention described in claim 8 is the same as that of claim 1
7. A portable device capable of using the battery pack according to any one of 7, wherein a built-in battery, a power supply terminal for supplying a DC power from the outside, and a main power source include the built-in battery or the power supply battery of the battery pack. At one time, battery check means for checking whether or not the main power supply is in a usable state, and when the battery pack is connected to the power supply terminal, it is transmitted by modulating the voltage output from the battery pack. Information detecting means for detecting information on the power supply battery, and when the information on the power supply battery is detected, the reference value for the judgment by the battery checking means is changed from the reference value for the built-in battery to the battery pack based on the information on the power supply battery. And a reference value changing means for changing to a reference value.

According to the above configuration, when the battery pack is connected to the power supply terminal, the information about the power supply battery transmitted by the modulation of the voltage output from the battery pack is detected, and the reference value for the judgment by the battery checking means is detected. Is changed from the reference value for the built-in battery to the reference value for the battery pack based on the information about the power supply battery.

As a result, when the portable device is driven by the built-in battery, for example, the output voltage of the battery is detected, and the battery voltage is compared with the reference value for the built-in battery to exhaust the built-in battery (that is, the built-in battery). When the battery pack is operating, the output voltage of the battery pack is compared with the reference value for the battery pack to determine the consumption state of the battery pack. It

Therefore, even if the built-in battery of the battery pack is different from the built-in battery of the portable device, the battery check can be properly performed.

[0029] According to a ninth aspect of the invention, in the portable device according to the eighth aspect, the information regarding the power supply battery is detected, and the power supply battery of the battery pack is limited in supply current from the information. At this time, a current limiting means for limiting the drive current of the device to a value smaller than the current value that can be supplied by the battery pack is further provided.

According to the above configuration, when the portable device is driven by the battery pack and the battery pack is of a type having a limited supply current, the drive current of the device is lower than the current value that can be supplied by the battery pack. Is also limited to small values. Therefore, the battery pack is not damaged by the excessive current supply.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION A battery pack according to the present invention and a portable device capable of using the battery pack will be described by taking an electronic still camera as an example.

FIG. 1 is a perspective view showing an overview of an embodiment of a battery pack according to the present invention.

The battery pack 1 has a rectangular parallelepiped box shape, and a display unit 3 for displaying the remaining capacity of the battery, the number of times of charging, etc. is provided on the upper side 2a of the pack main body 2.
On the left side thereof, indicator lamps 4 and 5 composed of two LEDs (light emitting diodes) are provided.

As will be described later, the pack main body 2 has a built-in rechargeable battery such as a lithium ion battery, a detection circuit for detecting the remaining capacity of the rechargeable battery, and a charging circuit for charging the rechargeable battery. As shown in the figure, the display unit 3 displays the remaining capacity Ps of the secondary battery as a percentage (%) (see display 31) and the number of times N the secondary battery has been charged (see display 32). ). The remaining capacity Ps of the battery may be displayed in electric power (mVAh). Further, the display unit 3 also displays a warning indicating that the battery has reached the end of its service life or the time to refresh (see display 33).

The upper indicator light 4 indicates that the battery pack 1 is connected to the portable device and is in a power supply state, and the lower indicator light 5 indicates that the battery pack 1 is being charged. To do.

A connection terminal (jack) 6 to which a power cord 7 for charging is connected is provided at the lower portion of the narrow side surface 2b which is in contact with the long side on the left side of the side surface 2a. Power cord 7
Is a connection plug 71 connected to an AC outlet at one end
Is provided, and a connection plug 72 connected to the connection terminal 6 is provided at the other end.

A power supply cord 8 for supplying power to a portable device is attached to the right end of the narrow side face 2c in contact with the upper short side of the side face 2a. Connection terminal (jack) for external power supply of equipment
A connection plug 81 that can be connected to (a connection terminal for connecting an AC adapter; hereinafter referred to as a DC jack) is provided.

FIG. 2 is a block diagram showing an example of the internal structure of the battery pack 1.

In the figure, the same members as those shown in FIG. 1 are designated by the same reference numerals. Step-down circuit 9 is 100v
The AC power is reduced to about 10 V and rectified into DC to generate a predetermined charging power.

The secondary battery 10 is a lithium ion battery.
This is connected in series. The standard output voltage of the secondary battery 10 is 7.0v, and the upper limit voltage VHl that can drive a portable device.
im and the lower limit voltage VLlim are 7.2v and 4.4v, respectively.

Although a lithium ion battery is used as the secondary battery 10 in the present embodiment, it may be another secondary battery such as a nickel hydrogen battery or a nickel cadmium battery. Alternatively, a primary battery such as a lithium battery may be used. When a nickel-hydrogen battery is used as the secondary battery 10, four batteries are connected in series and the standard output voltage is 4.8v.
Then, the upper limit voltage VHlim and the lower limit voltage VLlim are 5.2, respectively.
v and 3.6v.

The voltage detection circuit 11 detects the output voltage Vp of the secondary battery 10. The voltage detection circuit 11 is formed by connecting two resistors in series, and divides the output voltage Vp of the secondary battery 10 by resistance to output it to the control unit 14.

The switch circuit 12 interrupts the output voltage of the secondary battery 10 to generate a transmission signal of information related to the secondary battery 10. Opening / closing control of the switch circuit 12 is performed by the control unit 14. As will be described later, the control unit 14 controls the battery type K (lithium ion battery in the present embodiment), the remaining battery capacity Ps, and the usable upper limit voltage VHli.
Information about the secondary battery 10 such as m and usable lower limit voltage VLlim (hereinafter referred to as battery information) is coded, and opening / closing of the switch circuit 12 is controlled based on this code signal.

FIG. 3 is a diagram showing an example of a transmission signal of battery information generated by interrupting the output voltage of the secondary battery 10.

As shown in the figure, the transmission signal includes the battery type K, the battery remaining capacity Ps, the upper limit voltage VHlim and the lower limit voltage V.
It is generated by encoding the information of Llim into a 16-bit code signal and intermittently outputting the output voltage Vp of the secondary battery 10 based on this code signal. That is, in the transmission signal, the output voltage Vp is 0 [v] when the bit is "0", and the output voltage Vp is Vp [v] when the bit is "1".
It is created by

The bit allocation of each information is as follows: battery type K: 3 bits, battery remaining capacity Ps [mVAh]: 5 bits, upper limit voltage VHlim [v]: 4 bits, lower limit voltage VLlim.
[V]: It has 4 bits.

In the present embodiment, the battery information to be transmitted does not include the number of times of charging N or the battery life, but such information is transmitted to the portable device and the portable device side indicates the replacement time of the battery pack 1 or the like. It may be displayed.

Further, in the present embodiment, the transmission signal is generated by interrupting the output voltage Vp of the secondary battery 10, but the transmission signal may be generated by another modulation method. For example, the transmission signal may be created by modulating the amplitude of the output voltage Vp using the battery information as a modulation signal.

Further, although the battery information is transmitted only once in the present embodiment, it may be transmitted a plurality of times. In this way, transmission errors can be reduced.

Returning to FIG. 2, the memory 13 is a memory for storing the number of charging times N. The memory 13 is composed of a nonvolatile memory such as an EEPROM or a flash memory.

When the connection plug 81 is connected to the DC jack of the portable device, the control unit 14 creates the battery information.
Various controls such as a transmission process of generating a transmission signal based on the battery information and transmitting the transmission signal to the portable device, management of battery life, charge control of the secondary voltage 10 and the like are performed.

The controller 14 detects that the connection plug 81 is connected to the DC jack of the portable device.
41, a charging / discharging detection unit 142 that detects the number of charging times N, the remaining capacity Ps, the battery life, etc. of the secondary battery 10, a voltage modulation unit 143 that creates a transmission signal, an LCD display unit 3 and indicators 4 and 5 are displayed. The display control unit 144 for controlling and the charging control unit 145 for controlling the charging operation of the secondary battery 10 are provided.

When a load is connected to the secondary battery 10, the connection detecting unit 141 lowers the output voltage thereof. Therefore, it is determined that the connection plug 81 is connected to the DC jack of the portable device based on the change of the output voltage. To detect.

The charge / discharge detection unit 142 calculates the remaining capacity Ps of the secondary battery 10 based on the voltage detected by the voltage detection circuit 11, and detects the discharged state and the charged state of the secondary battery 10. The charging / discharging detection unit 142 reads the number of times of charging N stored in the memory 13 each time the charging operation is detected, increases the number of times N by 1, and then stores the number of times N in the memory 13 again. As a result, the integrated value of the number of charging times N is sequentially stored in the memory 13 for each charging.

When the charging / discharging detection unit 142 stores the charging number N again in the memory 13, the charging / discharging detecting unit 142 compares it with a preset threshold value Ns of the charging number. When the charging number N exceeds the threshold value Ns, the secondary battery 10 is charged. The warning signal is generated and output to the LCD display unit 3 by determining the end of the life (in the case of a battery having a memory effect such as a nickel-hydrogen battery, the time of refreshing).

When the connection detection unit 141 detects that the connection plug 81 is connected to the DC jack of the portable device, the voltage modulation unit 143 detects the remaining capacity Ps of the secondary battery 10 based on the voltage detected by the voltage detection circuit 11. And the calculated result is coded and combined with the previously coded information of the battery type K, the upper limit voltage VHlim, and the lower limit voltage VLlim to generate a transmission signal. Then, the battery information is transmitted to the mobile device by disconnecting the switch circuit 12 based on the transmission signal.

When the connection detection unit 141 detects that the connection plug 81 is connected to the DC jack of the portable device, the display control unit 144 turns on the indicator lamp 5. Also,
The display control unit 144 causes the LCD display unit 3 to display the remaining capacity Ps of the secondary battery 10 detected by the charge / discharge detection unit 142, and when the charge / discharge detection unit 142 detects the state of charge of the secondary battery 10, The indicator lamp 4 is turned on. Furthermore, when the battery life is detected by the charge / discharge detection unit 142, a warning display is displayed on the LCD display unit 3.

The charge controller 145 controls the charging of the secondary battery 10 by the step-down circuit 9. When the connection plug 71 of the power cord 7 is connected to an AC outlet and AC power is input to the step-down circuit 9, a predetermined charging voltage is output from the step-down circuit 9 and charging of the secondary battery 10 is started. The charging control unit 145 determines from the battery voltage detected by the voltage detection circuit 11 whether or not the secondary battery 10 is in a fully charged state, and when it is in a fully charged state, stops the charging operation of the step-down circuit 9. .

As described above, in the battery pack 1 according to the present embodiment, when the connection plug 81 of the power supply cord 8 is connected to the DC jack of the portable device, the connection detection unit 141 detects the connection, and the battery pack 1 is built in. The output voltage Vp of the secondary battery 10 is intermittently transmitted, and the battery information is transmitted to the mobile device.

Therefore, the portable device receives the transmission signal, and based on the transmitted battery information, appropriate battery check control can be performed on the externally connected battery pack 1 in the same manner as the built-in battery of the portable device. It will be possible. A portable device that can use the battery pack 1 according to the present embodiment and battery check control in the portable device will be described later.

Further, in the battery pack 1 according to the present embodiment, the remaining capacity Ps of the built-in secondary battery 10 is detected and constantly displayed on the LCD display section 3. For this reason, the user is required to drive the portable device and the battery pack 1
It is possible to easily know the charging time of the battery and prevent serious accidents such as data being damaged due to insufficient power supply of the battery pack 1 during processing such as reading / writing data from / to the memory.

When the battery pack 1 is connected to the AC power source by the power cord 7, the step-down circuit 9 operates to charge the secondary battery 10. Therefore, when the battery capacity of the battery pack 1 is exhausted, the power can be supplied again by charging.

The number N of times of charging is stored in the memory 13, and the life of the battery and the time of refreshing are discriminated each time the secondary battery 10 is charged, and the warning is displayed when the life of the battery or the like is reached. . Therefore, the user can easily know when to replace the battery pack 1 or when to refresh it.

Next, a portable device in which the battery pack 1 according to this embodiment can be used will be described using an electronic still camera as an example.

FIG. 4 is a front view showing an outline of one embodiment of the electronic still camera according to the present invention, and FIG. 5 is a rear view of the same electronic still camera.

The electronic still camera 20 is provided with a taking lens 21 in the center of the front surface, and a photometry section 22 for measuring the subject brightness on the upper part thereof, and the subject distance is measured on the left side of the photometry section 22. A distance measuring unit 23 is provided, and a flash 24 is provided on the right side of the photometric unit 22.

On the upper surface of the electronic still camera 20,
A shutter button 25 is provided at the left end. In the shutter button 25, the S1 switch for instructing the preparation of shooting such as focus adjustment and exposure control value setting is turned on when the shutter button 25 is half pressed,
This is an operation button for turning on the S2 switch for instructing the release when fully pressed. A power switch 26 and a card insertion slot 27 into which a memory card 30 is attached are provided on the lower side surface of the electronic still camera 20.
A card eject button 28 for ejecting the memory card 30 is provided on the upper portion of the card 7.

On the rear surface of the electronic still camera 20, as shown in FIG. 5, an LCD (Liquid Crystal Displa
A display unit 31 (hereinafter, referred to as LCD display unit 31) including y) is provided.

The LCD display unit 31 functions as a display device for reproducing and displaying a photographed image and also as an electronic view finder. That is, in the reproduction mode, the designated captured image is displayed on the LCD display unit 31, and in the recording mode, the still image captured by the operation of the shutter button 25 by the photographer is displayed on the LCD display unit 3.
1, the photographer can confirm the photographed image immediately after the release and the photographed image recorded in the memory card 30.

When the electronic still camera 20 is activated, video shooting is performed by the image pickup device 33 (see FIG. 6) described later, and the shot image is displayed on the LCD display section 31,
This allows the photographer to monitor the subject within the photographing screen.

A still image display cancel button 32 is provided on the left side of the LCD display section 31. The still image display cancel button 32 restores the display mode of the LCD display unit 31, which is automatically switched from the moving image display to the still image display each time the shooting process is performed, from the still image display to the moving image display for the next shooting. Is an operation button for.

The reason why the display mode is manually returned by the photographer is to improve the convenience of monitoring the photographed image without fixing the monitor time.

FIG. 6 is a block diagram showing the internal structure of the electronic still camera 20.

In the figure, the same members as those shown in FIGS. 4 and 5 are designated by the same reference numerals.

The image pickup device 33 photoelectrically converts the subject light image transmitted through the taking lens 21 into an image signal and takes in the image signal. The image sensor 33 is, for example, a CCD (Charge-Coupled).
R, G, B in each pixel of the area sensor
The color filter is composed of a single plate type color area sensor arranged in a checkered pattern. The area sensor is not limited to the CCD type area sensor, but M
It may be an OS type area sensor.

The signal processing section 34 includes an image sensor 33 (hereinafter,
It is called CCD33. ) Performs predetermined analog signal processing on the image signal (analog signal) output from (1).
The signal processing unit 34 has a CDS circuit (correlated double sampling circuit) and an AGC (auto gain control) circuit. The CDS circuit reduces noise in the image signal and the AGC circuit adjusts the level of the image signal.

The A / D converter 35 converts the image signal output from the signal processor 34 into a digital image signal having a 10-bit structure (hereinafter, this digital image signal is referred to as image data).

Timing generator (TG) 36
Is a CCD 33, a signal processor 34, and an A / D converter 35.
It generates various timing pulses for controlling the driving of the.

In the electronic still camera 1 according to this embodiment, the diaphragm is a fixed diaphragm, and the exposure control is performed by the CCD 3 corresponding to the exposure amount of the CCD 33, that is, the shutter speed.
This is performed by adjusting the charge storage time of 3.

Timing generator 36 (hereinafter T.
Notated as G36. ) Has an internal clock, and based on a reference clock generated by this clock, for example, a timing signal of integration start / end (exposure start / end) or a read control signal of a light reception signal of each pixel (horizontal synchronization signal, vertical Sync signal, transfer signal, etc.)
Output to D33.

The T / G 36 also generates a timing signal for performing signal processing of the image signal read from the CCD 33 (a signal consisting of a time-series signal of the light receiving signal of each pixel), and the signal processing unit 34 and A / It is output to the D conversion unit 35. The signal processing unit 34 performs the above-described analog signal processing on the light reception signal of each pixel in synchronization with this timing signal, and the A / D conversion unit 35 synchronizes the light reception signal of each pixel with a digital signal in synchronization with this timing signal. Convert to.

The image data processing section 37 performs predetermined data processing such as black level correction, white balance adjustment, gamma correction, and data interpolation for insufficient pixel positions on the image data. The image data processing unit 37 uses R, G,
Predetermined data processing is performed for each image data of the B color component.

The image memory 38 is a buffer memory for temporarily storing the image data after data processing. The image memory 38 has a capacity capable of storing image data (frame image data) of R, G, and B color components, respectively.

The VRAM 39 displays the image on the LCD display unit 31.
It is a display buffer memory that stores image data that constitutes the image to be displayed on. The VRAM 39 has a capacity capable of storing at least image data having the same pixel density as that of the LCD display unit 31.

The AF control section 40 drives the focusing lens of the taking lens 21 to adjust the focus of the taking lens 21. As shown in FIG. 7, the AF control unit 40 includes a DC motor 4 that is a driving source of the focusing lens.
01 and PWM for controlling the drive of this DC motor 401
(Pulse width modulation) chopper circuit 402.

DC power for driving is supplied to the PWM chopper circuit 402 from a power feeding section 435, which will be described later, and PWM
The chopper circuit 402 is the DC motor 401 of this DC power supply.
The drive of the DC motor 401 is controlled by intermittently supplying power to the DC motor 401.

The contents of this AF control are described in the control section 4 which will be described later.
4 is performed. The control unit 44 calculates the drive amount of the DC motor 401 based on the subject distance detected by the distance measuring unit 23, and operates the PWM chopper circuit 402 based on the calculation result. As a result, the DC motor 401 is driven in a predetermined direction by a predetermined amount, and the focusing lens in the taking lens 21 is set to the in-focus position.

Further, the D by the PWM chopper circuit 402
The method of supplying the C power to the DC motor 401 is as follows:
It is controlled by a B / C control unit 441 therein depending on the type of main power source. That is, for example, when the main power source is a battery such as a lithium ion battery that cannot pass a large current, the pulse width of the drive pulse of the PWM chopper circuit 402 is narrowed by the B / C control unit 441 (that is, DC).
The power supply period to the DC motor 401 of the power supply is shortened).
This suppresses large current consumption in the AF control unit 40,
Damage to the main power battery is prevented.

The FL light emission control section 41 controls the light emission of the flash 25. The FL light emission control unit 41 is shown in FIG.
As shown in FIG. 7, a charging circuit including a switching circuit 411, a step-up transformer T, a rectifying circuit 412, a voltage detection circuit 413, and a PWM control circuit 414, and a main capacitor 415 that stores flash emission energy (charge).
And a trigger circuit 416 for controlling discharge of the electric charge accumulated in the main capacitor 415.

The flash 24 is composed of a xenon tube, and the accumulated charge in the main capacitor 415 is discharged to generate flash light.

A light emission signal control signal is inputted from the control section 44 to the trigger circuit 416, and the trigger circuit 416 synchronizes with the light emission control signal and the main capacitor 4
The discharge of the accumulated charge of 15 to the flash 24 and the stop of the discharge are controlled.

The switching circuit 411 has a power feeding portion 435.
DC power for charging is supplied from the PWM control circuit 41.
A charging control signal is input to the controller 4 from the controller 44.

When the charge control signal is input from the control unit 44, the PWM control circuit 414 outputs a drive signal composed of a pulse signal to the switching circuit 411. The switching circuit 411 uses the step-up transformer T based on this pulse signal.
The DC voltage applied to the primary coil is interrupted, the AC voltage boosted by this is induced in the secondary coil, and the DC power supplied from the DC power source is transmitted to the secondary side of the step-up transformer T. The AC voltage induced in the secondary coil of the step-up transformer T is rectified into a DC by the rectifier circuit 412 and applied to the main capacitor 415, whereby the main capacitor 415 is charged.

The voltage between the terminals of the capacitor 415 is detected by the voltage detection circuit 413. When the detected voltage reaches a predetermined full charge voltage, the voltage detection circuit 413 outputs a charge stop signal to the PWM control circuit 414. When the charge stop signal is input, the PWM control circuit 414 stops the charging operation (output of the pulse signal), which causes the main capacitor 4
Overcharging of 15 is prevented.

The charging operation of the PWM control circuit 414 is controlled by the control unit 44, and the charging current during the charging is further controlled by the B / C control unit 441 in the control unit 44 according to the type of the main power source. To be done. That is, for example, when the main power source is a battery such as a lithium-ion battery that cannot pass a large current, the pulse width of the pulse signal output from the PWM control circuit 414 to the chopper circuit 411 is B.
The width is narrowed by the C control unit 441 (that is, the power supply period to the primary coil of the step-up transformer T is shortened). This suppresses the large current consumption in the FL light emission control unit 41,
Damage to the main power battery is prevented.

Returning to FIG. 6, the card I / F 42 controls the driving of the memory card 30, records image data in the memory card, and reads image data recorded in the memory card.

The power supply controller 43 controls the supply of drive power to various processing units and processing circuits in the electronic still camera 1.

The power control unit 43 has a built-in battery 431 composed of a primary dry battery such as a lithium battery, and an external power supply discriminating unit 432 for discriminating whether the external power supply connected to the DC jack 29 is the AC adapter or the battery pack 1. , DC
When the AC adapter (not shown) or the battery pack 1 is connected to the jack 29, the main power source is the built-in battery 431.
Switch circuit 433 for switching from the external power supply to the external power supply, the voltage detection unit 434 for detecting the voltage of the main battery supplied from the internal battery 431 or the external power supply, and the DC power supplied from the main power supply drive each processing unit and each processing circuit. Included is a power supply unit 435 that is supplied by being transformed into a prescribed power supply.

Upon detecting the DC voltage, the external power supply discriminating unit 432 detects that the external power supply is connected to the DC jack 29. This detection information is input to the control unit 44, and the control unit 44 switches the switch circuit 433 from the internal battery 431 to the external DC power source based on this detection information.

Further, the external power source discriminating unit 432 is set for a predetermined period,
DC voltage change is detected, and when there is no voltage change, DC
It is determined that the AC adapter is connected to the jack 29, and the determination result is input to the control unit 44. If there is a voltage change, it is determined as a transmission signal from the battery pack 1, the battery information is decoded from the voltage change, and the decoding result is input to the control unit 44.

The voltage detector 434 detects the output voltage of the main power source and inputs it to the controller 44. The control result of the determination result of the external DC power supply, the battery information, and the detected voltage of the main power supply are displayed.
It is input to the B / C control unit 441 in the inside and used for the check control of the main power supply described later.

The control section 20 is composed of a microcomputer, and has the above-mentioned T / G 36, image data processing section 37, image memory 38, VRAM 39, LCD display section 31, AF.
The control unit 40, the FL light emission control unit 41, the memory I / F 42, and the like are driven to control the shooting operation of the electronic still camera 20 as a whole.

Although not shown, the control unit 44
Has a function of compressing / expanding image data, and when recording a captured image in the memory card 30, the image data temporarily stored in the image memory 38 is compressed by the JPEG method and recorded in the memory card 30. Further, when the captured image recorded in the memory card 30 is reproduced on the LCD display unit 31,
After the image data (compressed data) read from the memory card 30 is expanded and temporarily stored in the image memory 38, the image size is adjusted again and output to the VRAM 39 for reproduction on the LCD display unit 31.

Further, when operating the LCD display 31 as an electronic viewfinder, the control unit 44 controls the CCD 3
3 is driven by video to capture the video image of the subject image, and the video images are sequentially stored in the VRAM 39 and L
It is displayed on the CD display unit 31.

Therefore, when the electronic still camera 20 is activated and the photographing mode is set, the control section 44 causes the CC
A moving image of the subject is captured at D33, and the captured image is subjected to predetermined signal processing and image data processing at the signal processing unit 34, the A / D conversion unit 35, and the image data processing unit 37, and then stored in the image memory 38. By temporarily recording and reading the recorded image in the VRAM 39, the viewfinder image of the subject is displayed on the LCD display unit 31 (viewfinder display).

When the shutter button 25 is fully pressed in this state to instruct photographing, the control section 44 detects the subject brightness by the photometry section 22 and the distance measurement section 23.
The subject distance is detected by and the exposure control value (integration time of the CCD 33) is set using the subject brightness. Also,
The AF controller 40 is operated based on the subject distance to adjust the focus of the taking lens 21.

Subsequently, the control unit 44 operates the CCD 33 based on the set exposure control value to pick up an image of the subject. At this time, when the flash 24 needs to emit light, the FL light emission control unit 4 synchronizes with the photographing operation of the CCD 33.
1 is operated and the flash 24 is made to emit light.

The control unit 44 converts the image signal of the photographed image into the signal processing unit 34, the A / D conversion unit 35 and the image data processing unit 3.
Predetermined signal processing in 7 (noise reduction, level adjustment, A / D
Conversion) and image data processing (black level correction, white balance adjustment, gamma correction, data interpolation, etc.) are performed and temporarily stored in the image memory 38.

Then, the image data is output to the VRAM 39 and displayed on the LCD display section 31, while the JPEG
The data is compressed by the method and recorded in the memory card 30.

In the reproduction mode, the control unit 44
Reads out image data (compressed data) of a captured image of a frame designated by an operation button (not shown) from the memory card 30, decompresses it into all image data, and temporarily records it in the image memory 38. Then, the image size is adjusted from the image memory 38 and the image data is read out to the VRAM 39 to reproduce and display the captured image on the LCD display unit 31.

The control unit 44 regularly monitors the consumption state of the main power source, and also performs a predetermined battery check control (hereinafter abbreviated as B / C control) according to the consumption state.

The control unit 44 includes a B / C control unit 441,
The B / C control unit 441 performs predetermined B / C control according to the procedure shown in FIG.

The flowchart shown in FIG. 9 is a B / C control processing procedure repeatedly executed by the B / C control unit 441 at a predetermined cycle.

In the battery check, the B / C control unit 441 first fetches from the power supply control unit 43 whether or not the external DC power supply is connected and the battery information data of the battery pack 1 (# 1, # 3).

From this data, if neither the AC adapter nor the battery pack 1 is externally connected (NO in # 1),
The process proceeds to step # 13 and the main power source (built-in battery 43
The output voltage Vout of 1) is detected (# 13), and the output voltage Vout is compared with a predetermined lower limit voltage VLlim (# 1).
5).

In this embodiment, the lower limit voltage VLlim of the built-in battery 431 is set to 3.6 [v], and Vout> VL
If lim (= 3.6v) (NO in # 15), the built-in battery 431 is normal, and the battery check is ended. On the other hand, if Vout ≦ VLlim (= 3.6v) (YES in # 15), the built-in battery 431 is exhausted to a state where normal shooting operation and playback operation are difficult, and it is time to replace the LCD display unit. A warning to that effect is displayed on 31 (# 17), and the battery check ends.

When the connection plug is connected to the DC jack 29 (YES in # 1), the switch circuit 433 is switched to switch the main power source from the internal battery 431 to the external DC power source (# 3).

Subsequently, it is judged from the change in the voltage supplied from the external DC power source whether or not the battery information is transmitted (# 5). If the battery information is not transmitted (N in # 5,
O), it is determined that the AC adapter is connected to the DC jack 29, and the process proceeds to step # 13.

In steps # 13 and # 15, the voltage of the main power supply is detected as described above, and a warning is displayed based on the detection result. However, when the AC adapter is connected, the detection voltage Vout is always Since the lower limit voltage VLlim is exceeded (NO in # 15), the battery check ends without displaying a warning.

On the other hand, if the battery information is transmitted (# 5
YES), the lower limit voltage VLlim for the B / C control is changed from the lower limit voltage VLlim for the internal battery 431 to the lower limit voltage VLlim of the battery pack 1 included in the battery information (# 7). In this embodiment, the battery pack 1
Since the lower limit voltage VLlim of B is 4.4 [v], the lower limit voltage VLlim for B / C control is 3.6 [v] to 4.4.
It is changed to [v].

Subsequently, the charge current control value in the FL light emission control section 41 is changed to a predetermined low current value for the lithium ion battery (# 9), and the control value of the motor drive current in the AF control section 40 is changed. It is changed to a predetermined low current value for the lithium-ion battery (# 11).

Subsequently, the output voltage Vout of the main power supply (battery pack 1) is detected (# 13), and the output voltage Vout is compared with a predetermined lower limit voltage VLlim for the battery pack 1 included in the battery information. (# 1
5).

If Vout> VLlim (= 4.4v) (NO in # 15), the battery pack 1 is normal and the battery check is terminated. On the other hand, Vout ≦ VL
If it is lim (= 4.4v) (YES in # 15), the battery pack 1 is exhausted to a state where normal shooting operation and reproduction operation are difficult, and it is time to replace, so the LCD display unit 3
A warning display to that effect is displayed in step 1 (# 17), and the battery check is terminated.

The battery information is D for the battery pack 1.
Since it is transmitted only when it is connected to the C jack 29, when the battery check is performed after the battery pack 1 is connected to the DC jack 29, the process proceeds from step # 5 to step # 13. The processes of steps # 7 to # 11 are not performed. That is, the low current control of the AF control unit 40 and the value FL light emission control unit 41 is maintained, and only the output voltage of the battery pack 1 (check of remaining capacity) is continued.

Further, in the present embodiment, the AF control and the FL light emission control have been described as an example of the case where a large current is required, but the same method is used for the other actuator control which requires a large current. It is preferable to control the pack 1 to perform low current control.

As described above, the electronic still camera 20
When the battery pack 1 is connected to the DC jack 29 for connecting the AV adapter, it becomes possible to receive the battery information transmitted by modulating the output voltage from the battery pack 1, and the control contents of the battery check based on this battery information. Is changed from the contents for the built-in battery 431 to the contents for the battery pack 1. Therefore, even when the battery pack 1 is externally connected to the DC jack 29, the B / C control appropriate for the battery pack 1 is performed. It can be performed.

Therefore, the electronic still camera 20 will not suddenly be stopped due to exhaustion of the battery pack 1. The user can replace or refresh the battery pack 1 at an appropriate time by the power consumption warning displayed on the LCD display unit 30.

When the battery pack 1 is composed of the type of secondary battery 10 that cannot supply a large current,
Since the power consumption of the electronic still camera 20 is changed to the low current consumption, the battery pack 1 is not damaged by the high current power supply.

In the above embodiment, an electronic still camera was described as an example of a portable device, but the present invention is not limited to this, and various types of devices such as a video camera, a portable personal computer, a portable recorder, etc. It can be applied to mobile devices.

[0130]

As described above, according to the present invention,
A battery pack used in a mobile device equipped with a power supply terminal for supplying DC power from the outside, and when the connection terminal is connected to the power supply terminal, based on the information about the power supply battery built into the battery pack. Since the information is transmitted to the mobile device at least once by modulating the output voltage of the power battery, even when the battery pack is connected to the power supply terminal, the information on the power battery is determined on the mobile device side. However, suitable power supply control can be performed by monitoring the power supply capacity of the battery pack based on the determination result.

Since the voltage modulation signal is generated by coding the information about the power supply battery and turning on / off the output voltage of the power supply battery based on the code signal, the transmission signal of the information about the power supply battery can be easily obtained. Can be generated.

Further, since the remaining capacity of the power supply battery is detected and the detection result is displayed, the user can easily know the power supply capacity and the consumption state of the battery pack.

Further, the power source battery is a rechargeable secondary battery, and the number of times of charging of this secondary battery is counted and displayed, or when the number of times of charging exceeds a predetermined prescribed number, a warning is displayed. , The user can easily estimate the life of the battery pack and, if possible, the time of refresh.

Further, according to the present invention, there is provided a portable device which can use the battery pack, wherein when the battery pack is connected to the power supply terminal, the power source is transmitted by modulating the voltage output from the battery pack. The reference value for detecting information about the battery and determining whether the power supply is in a usable state is changed from the reference value for the built-in battery to the reference value for the battery pack based on the information about the power supply battery. Therefore, even when the type of the battery pack is different from the built-in battery of the mobile device, the battery check can be appropriately performed on the battery pack.

Furthermore, when the power supply battery of the battery pack is of a type in which the supply current is limited, the drive current of the device is limited to a value smaller than the current value that can be supplied by the battery pack, so it is excessive. The current supply does not damage the battery pack.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overview of an embodiment of a battery pack according to the present invention.

FIG. 2 is a block diagram showing an example of an internal configuration of a battery pack according to the present invention.

FIG. 3 is a diagram showing an example of a transmission signal of battery information generated by interrupting an output voltage of a secondary battery.

FIG. 4 is a front view of an electronic still camera according to the present invention.

FIG. 5 is a rear view of the electronic still camera according to the present invention.

FIG. 6 is a block diagram showing an internal configuration of an electronic still camera according to the present invention.

FIG. 7 is a diagram illustrating an example of an internal configuration of an AF emission control unit.

FIG. 8 is a diagram showing an example of an internal configuration of an FL control unit.

FIG. 9 is a flowchart showing a processing procedure of B / C control of the electronic still camera according to the present invention.

[Explanation of symbols]

1 Battery Pack 2 Pack Main Body 3 Display (Display Means) 4, 5 Indicator Light 6 Connection Terminal 7 Power Cord 8 Power Cord 81 Connection Plug (Connection Terminal) 9 Step-Down Circuit (Charging Means) 10 Secondary Battery (Power Battery) 11 Voltage detection circuit (constituent element of remaining capacity detection means) 12 Switch circuit (constituent element of voltage modulation means) 13 Memory (storage means) 14 Control section 141 Connection detection section (detection section) 142 Charge / discharge detection section (remaining capacity detection section) , Counting means, discriminating means) 143 voltage modulation section (voltage modulation section) 144 display control section (display control section) 145 charging control section 20 electronic still camera (portable device) 21 shooting lens 22 photometry section 23 distance measurement section 24 flash 25 Shutter button 26 Power switch 29 DC jack (power supply terminal) 30 Memory card 31 LCD display unit (display means) 3 3 Image sensor 34 Signal processing unit 35 A / D conversion unit 36 Timing generator 37 Image data processing unit 38 Image memory 39 VRAM 40 AF control unit 402 PWM chopper circuit 41 FL light emission control unit 414 PWM control circuit 43 Power supply control unit 431 Built-in battery 432 External power supply discriminating unit (information detecting unit) 433 Switch circuit 434 Voltage detecting unit 435 Power feeding unit 44 Control unit 441 B / C control unit (battery checking unit, reference value changing unit, current limiting unit)

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-285026 (JP, A) JP-A-11-41828 (JP, A) JP-A-9-7640 (JP, A) Actual Kaihei 3- 86744 (JP, U) Actual Kaihei 2-77733 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G06F 1/28 H01M 2/10 H01M 10/48 H02J 7/00

Claims (9)

(57) [Claims] 1. A battery pack used for a mobile device having a power supply terminal for supplying a DC power from the outside, comprising a power supply battery and a direct current from the power supply battery to the mobile device via the power supply terminal. A connection terminal connected to the power supply terminal to supply electric power, a detection unit that detects that the connection terminal is connected to the power supply terminal, and a power supply when the connection terminal is connected to the power supply terminal. At least one for transmitting information about the battery to the portable device.
And a voltage modulation unit that modulates the output voltage of the power supply battery based on the information. 2. The battery pack according to claim 1, wherein the voltage modulating means encodes information relating to the power supply voltage, and turns on / off the output voltage of the power supply battery based on the code signal. Battery pack characterized by. 3. The battery pack according to claim 2, wherein the information about the power source battery includes at least the type of battery, a usable upper limit voltage and a usable lower limit voltage. 4. The battery pack according to claim 3, further comprising a remaining capacity detecting means for detecting a remaining capacity of the power supply battery, wherein the information about the power supply battery further includes a remaining capacity of the battery. Battery pack to do. 5. The battery pack according to claim 4, further comprising display means and display control means for displaying the remaining capacity of the power supply battery detected by the remaining capacity detection means. battery pack. 6. The battery pack according to claim 5, wherein the power supply battery comprises a rechargeable secondary battery, charging means for the secondary battery, and counting means for counting the number of times the secondary battery is charged. Non-volatile storage means for storing the number of times of charging the secondary battery counted by the counting means, wherein the display control means further displays the number of times of charging stored in the storage means on the display means. A battery pack characterized in that. 7. The battery pack according to claim 6, further comprising a determining unit that determines whether or not the number of times of charging counted by the counting unit exceeds a preset specified number of times, and the display control unit includes: Further, the battery pack is configured to display a warning on the display means when the number of times of charging exceeds the specified number of times. 8. A portable device that can use the battery pack according to any one of claims 1 to 7, wherein a built-in battery, a power supply terminal for supplying a DC power supply from the outside, and a main power supply are built-in. When it is a battery or a power supply battery of the battery pack, a battery check means for checking whether the main power supply is in a usable state, and when the battery pack is connected to the power supply terminal, When information detecting means for detecting information about the power supply battery transmitted by modulating the output voltage and information about the power supply battery are detected, a reference value for judgment by the battery checking means is calculated from the reference value for the built-in battery. Reference value changing means for changing the reference value for the battery pack based on the information about the power supply battery A mobile device characterized by being provided. 9. The portable device according to claim 8, wherein information about the power supply battery is detected, and when the power supply battery of the battery pack is of a type in which the supply current is limited from the information, the drive current of the device is set to the above-mentioned value. A portable device further comprising current limiting means for limiting a current value that can be supplied by the battery pack to a smaller value.