|
Digital Camera Patent Abstract
In the digital camera that can be used in connection to a mobile
phone or other mobile electronic devices and the system thereof,
a battery mounted in each device is shared to allow power to be
supplied between the devices, and allow both devices to be used
for longer hours. The digital camera and the mobile phone are electrically
connectable by a connection cable. Generally, a power supply selection
switch is set to A, and a power supply selection switch is set to
D. The digital camera receives power supplied from a battery, and
the mobile phone receives power supplied form a battery. From this
state, when the power supply selection switch is switched to C,
power is supplied from the battery to the mobile phone. On the other
hand, when the power supply selection switch is set to B, and the
power supply selection switch is set to D, power is supplied from
the battery of the mobile phone to the digital camera.
Digital Camera Patent Claims
1. A digital camera connectable to a mobile electronic device capable
of being driven by a battery, the digital camera comprising: a first
battery which provides a supply source of power necessary to operate
the digital camera; a connecting unit which electrically connects
to the mobile electronic device; a power input terminal which receives
power supplied from a second battery mounted in the mobile electronic
device connected via the connecting unit; and a power supply selection
device which selectively switches a power supply such that power
is supplied from one of the first battery and the second battery.
2. The digital camera according to claim 1, further comprising
a power output terminal capable of supplying power from the second
battery to the mobile electronic device connected via the connecting
unit.
3. The digital camera according to claim 2, wherein the connecting
unit is also used as a remote control connecting unit to which a
remote control device is connected.
4-10. (canceled)
11. The digital camera according to claim 1, wherein the connecting
unit is also used as a remote control connecting unit to which a
remote control device is connected.
12-18. (canceled)
19. A digital camera connectable to a mobile electronic device
capable of being driven by a battery, the digital camera comprising:
a battery which provides a supply source of power necessary to operate
the digital camera; a connecting unit which electrically connects
to the mobile electronic device; and a power output terminal capable
of supplying power from the battery mounted in the digital camera
to the mobile electronic device connected via the connecting unit.
20. The digital camera according to claim 19, wherein the connecting
unit is also used as a remote control connecting unit to which a
remote control device is connected.
21. A digital camera system capable of transferring image data
by connecting a mobile electronic device capable of being driven
by a battery and a digital camera, wherein: the digital camera comprises:
a first battery which provides a supply source of power necessary
to operate the digital camera; a first connecting unit which electrically
connects to the mobile electronic device; a first power input terminal
which receives power supplied from a second battery mounted in the
mobile electronic device connected via the first connecting unit;
a first power supply selection device which selectively switches
a power supply such that power is supplied from one of the first
battery and the second battery; and a first power output terminal
capable of supplying power from the first battery to the mobile
electronic device connected via the first connecting unit; the mobile
electronic device comprises: a second battery which provides a supply
source of power necessary to operate the mobile device; a second
connecting unit which electrically connects to the digital camera;
a second power input terminal which receives power supplied from
the first battery mounted in the digital camera connected via the
second connecting unit; a second power supply selection device which
selectively switches a power supply such that power is supplied
from one of the first battery and the second battery; and a second
power output terminal capable of supplying power from the second
battery to the digital camera connected via the second connecting
unit; and the first connecting unit and the second connecting unit
are used so that the first power input terminal and the second power
output terminal are connected and the first power output terminal
and the second power input terminal are connected to allow power
to be supplied between the digital camera and the mobile electronic
device.
Digital Camera Patent Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a digital camera and a
system thereof, and more particularly to a digital camera and a
system thereof that can be used in connection to a mobile electronic
device such as a mobile phone or a Personal Digital Assistant (PDA).
[0003] 2. Description of the Related Art
[0004] Systems have been proposed which allow a mobile phone and
a digital camera to be used in connection to each other (Japanese
Utility Model Registration No. 3074054, Japanese Patent Application
Publication No. 2000-197161). In these systems, a battery is mounted
to each of the mobile phone and the digital camera, and power is
separately supplied. A digital camera of a plug connection type
disclosed in Japanese Utility Model Registration No. 3074054 has
no battery, and power for the camera is supplied from a mobile phone.
[0005] However, in the conventional systems, if the battery of
either the mobile phone or the digital camera is drained and cannot
supply necessary power, the device naturally cannot be used.
SUMMARY OF THE INVENTION
[0006] The present invention is achieved in view of the above,
and has an object to provide a digital camera and a system of the
same that can be used in connection to a mobile phone or other mobile
electronic devices, wherein even if a battery of either the mobile
phone or the digital camera is drained, a power supply is shared
to allow use of both devices.
[0007] In order to attain the above described object, the present
invention is directed to a digital camera connectable to a mobile
electronic device capable of being driven by a battery, the digital
camera comprising: a first battery which provides a supply source
of power necessary to operate the digital camera; a connecting unit
which electrically connects to the mobile electronic device; a power
input terminal which receives power supplied from a second battery
mounted in the mobile electronic device connected via the connecting
unit; and a power supply selection device which selectively switches
a power supply such that power is supplied from one of the first
battery and the second battery.
[0008] According to the present invention, the digital camera is
connectable to the mobile electronic device via the connecting unit.
When the first battery mounted in the digital camera is drained
and cannot drive the camera, a power supply source is switched by
a power supply selection device, and power is supplied from the
second battery of the mobile electronic device to the digital camera.
This allows the digital camera to operate. The power supply selection
device may be a selection device which can be manually operated,
or may be a selection device which is automatically switched by
a control signal.
[0009] Preferably, the digital camera further comprises a power
output terminal capable of supplying power from the second battery
to the mobile electronic device connected via the connecting unit.
Thus, the digital camera and the mobile electronic device can share
their batteries with each other, so that the digital camera and
the mobile electronic device can be generally operated by their
respective batteries independently, but when one of the batteries
is drained, power is supplied from the other battery to allow operation.
[0010] The present invention is also directed to a digital camera
connectable to a mobile electronic device capable of being driven
by a battery, the digital camera comprising: a battery which provides
a supply source of power necessary to operate the digital camera;
a connecting unit which electrically connects to the mobile electronic
device; and a power output terminal capable of supplying power from
the battery mounted in the digital camera to the mobile electronic
device connected via the connecting unit.
[0011] According to the present invention, the digital camera is
connectable to the mobile electronic device via the connecting unit.
When the battery mounted in the mobile electronic device is drained
to prevent the mobile electronic device from being used, the digital
camera is connected to the mobile electronic device, thus allowing
power to be supplied from the battery of the digital camera to the
mobile electronic device. This allows the mobile electronic device
to operate.
[0012] Preferably, the connecting unit is also used as a remote
control connecting unit to which a remote control device is connected.
[0013] Preferably, the digital camera further comprises: a detecting
device which detects the power supply selected by the power supply
selection device; and a control device which operates to reduce
power consumption of the digital camera when the detecting device
detects a state where the power is supplied from the second battery
to the digital camera.
[0014] Preferably, as the operation to reduce the power consumption
of the digital camera, the control device performs at least one
of operations comprising supplying power to an image display device,
stopping supplying power to a flash circuit, and reducing a clock
operation frequency.
[0015] Preferably, the control device supplies power to an image
pickup circuit system only when the detecting device detects the
state where the power is supplied from the second battery to the
digital camera and the digital camera is set to an image-capturing
mode.
[0016] The image pickup circuit system includes an image pickup
device which converts an optical image to an electric signal, and
an analog signal processing circuit which performs sampling, color
separation, and gain control, of an image signal output from the
image pickup device.
[0017] Preferably, the digital camera further comprises a communication
device which sends power supply switching information to the mobile
electronic device when the detecting device detects the state where
the power is supplied from the second battery to the digital camera.
[0018] Preferably, the digital camera further comprises: a battery
remaining amount determining device which determines remaining amount
of the first battery; and a power supply switching control device
which automatically controls switching the first power supply selection
device such that power is supplied from the second battery when
the battery remaining amount determining device determines that
the remaining amount of the first battery is below a predetermined
reference value.
[0019] The present invention is also directed to a digital camera
system capable of transferring image data by connecting a mobile
electronic device capable of being driven by a battery and a digital
camera, wherein: the digital camera comprises: a first battery which
provides a supply source of power necessary to operate the digital
camera; a first connecting unit which electrically connects to the
mobile electronic device; a first power input terminal which receives
power supplied from a second battery mounted in the mobile electronic
device connected via the first connecting unit; a first power supply
selection device which selectively switches a power supply such
that power is supplied from one of the first battery and the second
battery; and a first power output terminal capable of supplying
power from the first battery to the mobile electronic device connected
via the first connecting unit; the mobile electronic device comprises:
a second battery which provides a supply source of power necessary
to operate the mobile device; a second connecting unit which electrically
connects to the digital camera; a second power input terminal which
receives power supplied from the first battery mounted in the digital
camera connected via the second connecting unit; a second power
supply selection device which selectively switches a power supply
such that power is supplied from one of the first battery and the
second battery; and a second power output terminal capable of supplying
power from the second battery to the digital camera connected via
the second connecting unit; and the first connecting unit and the
second connecting unit are used so that the first power input terminal
and the second power output terminal are connected and the first
power output terminal and the second power input terminal are connected
to allow power to be supplied between the digital camera and the
mobile electronic device.
[0020] According to the present invention, in the system where
the mobile electronic device and the digital camera are connectable,
both power supplies can be shared, so that if one of the batteries
is drained, power is supplied from the other battery to allow operation.
[0021] Preferably, a circuit is configured such that the first
battery and the second battery are not electrically connected to
each other in any setting states of the first power supply selection
device and the second power supply selection device.
[0022] Preferably, the digital camera further comprises: a detecting
device which detects the power supply selected by the first power
supply selection device; a first control device which operates to
reduce power consumption of the digital camera when the detecting
device detects a state where the power is supplied from the second
battery to the digital camera; and a communication device which
sends power supply switching information to the mobile electronic
device when the detecting device detects the state where the power
is supplied from the second battery to the digital camera; and the
mobile electronic device further comprises: a second control device
which operates to reduce power consumption of the mobile electronic
device based on the power supply switching information sent from
the digital camera.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The nature of this invention, as well as other objects and
advantages thereof, will be explained in the following with reference
to the accompanying drawings, in which like reference characters
designate the same or similar parts throughout the figures and wherein:
[0024] FIG. 1 shows a connection state between a digital camera
and a mobile phone according to an embodiment of the invention;
[0025] FIG. 2 shows a circuit of essential portions and a connection
relationship between the digital camera and the mobile phone;
[0026] FIG. 3 shows a circuit of essential portions according to
another embodiment;
[0027] FIG. 4 is a block diagram of internal configurations of
the digital camera and the mobile phone shown in FIG. 3;
[0028] FIG. 5 is a flowchart of a control procedure of the digital
camera of this embodiment;
[0029] FIG. 6 is a flowchart of a control procedure of automatic
switching of power supplies;
[0030] FIG. 7 shows a circuit of essential portions and a state
where the mobile phone is connected to the digital camera; and
[0031] FIG. 8 shows a circuit of essential portions and a state
where a remote control device is connected to the digital camera.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] Now, preferred embodiments of a digital camera and a system
of the same according to the invention will be described with reference
to the accompanying drawings.
[0033] FIG. 1 shows a connection state between a digital camera
and a mobile phone according to an embodiment of the invention.
A digital camera 10 has a shutter-release button 12 on its top,
and image data taken in accordance with pressing the shutter-release
button 12 is recorded in a recording medium such as a memory card
14. For the recording medium, various media can be used such as
SmartMedia (Solid-State Floppy Disk Card), a PC card, CompactFlash,
a magnetic disk, an optical disk, a magneto-optical disk, or Memory
Stick. A signal processing device and a media interface in accordance
with a medium to be used are applied. Not only a removable medium,
but also a recording medium included in the digital camera 10 (internal
memory) may be used.
[0034] The camera has, on its rear, a finder 16, a power supply
switch 17, a liquid crystal monitor (LCD) 18, a mode selection switch
19, a display panel 20, a cross button 21, a menu/enter button 22,
a cancel button 23, and a power supply selection switch 24 (SW 1).
The power supply switch 17 is an operating unit for turning on/off
a main power supply of the digital camera 10. The mode selection
switch 19 is a mode setting device which can be selectively switched
between an image-capturing mode and a reproduction mode. The display
panel 20 includes a small liquid crystal display which mainly displays
texts or simple symbols such as mode information or the number of
possible images to be captured.
[0035] The cross button 21 is a multifunction operating unit which
can input instructions of four directions: left, right, top, and
bottom. A left key functions as a one frame reversing button, a
right key functions as a one frame forwarding button in playback
mode, and a top key and a bottom key are used as zoom keys for adjusting
zoom in a playback zoom function or an electronic zoom function
in image-capturing. The cross button 21 also function as an operation
button for selecting menu items from a menu screen displayed by
pressing the menu/enter button 22 and for instructing to select
various setting items in each menu. The menu/enter button 22 is
used when moving from a normal screen to a menu screen in each mode,
or when confirming selection contents, instructing to perform (confirm)
processing, or the like. The cancel button 23 is used when canceling
an item selected from the menu, or returning to a previous operation
state.
[0036] The liquid crystal monitor 18 can be used as an electronic
finder for confirming an angle of view in image-capturing, and display
a preview of a captured image or a reproduced image read from the
memory card 14. Selecting the menu by the cross button 21 and setting
the various setting items are performed using a display screen of
the liquid crystal monitor 18. Further, the liquid crystal monitor
18 displays information such as the number of possible frames to
be captured (for moving images, possible hours for image-capturing),
a number of a reproduced frame, presence or absence of flash firing,
macro mode, recording quality, or the number of pixels.
[0037] The camera has, on its bottom, a media slot (not shown)
into which the memory card 14 is inserted, and a battery insert
port (not shown) into which a battery 26 is inserted. Generally,
the power supply selection switch 24 of the digital camera 10 is
set to A, and the digital camera 10 receives power supplied from
the battery 26, but switching the power supply selection switch
24 to B as required allows the digital camera 10 to receive power
from a battery 42 of a mobile phone 40.
[0038] The camera has, on its side, a connector 28 which electrically
connects to the mobile phone 40, and a voice output terminal (earphone
jack) 29.
[0039] The mobile phone 40 also has a connector 44 which electrically
connects to the digital camera 10, and one plug 51 of a connection
cable 50 is inserted into the connector 44 of the mobile phone 40,
and the other plug 52 is inserted into the connector 28 of the digital
camera 10, thereby providing electrical connection between the digital
camera 10 and the mobile phone 40 via the connection cable 50.
[0040] The mobile phone 40 has an antenna 45, a liquid crystal
display unit 46, an operation key 47, and a power supply selection
switch 48 (SW2), and the rechargeable battery 42 is mounted to its
rear. Generally, the power supply selection switch 48 of the mobile
phone 40 is set to D, and the mobile phone 40 receives power supplied
from the battery 42, but switching the power supply selection switch
48 to C as required allows the mobile phone 40 to receive power
from the battery 26 of the digital camera 10.
[0041] FIG. 2 shows a circuit of essential portions and a connection
relationship between the digital camera 10 and the mobile phone
40. A first pin PD1 of the connector 28 in the digital camera 10
connects to the ground (GND). A second pin PD2 connects to a cathode
of the battery 26 and a contact A terminal of the power supply selection
switch 24. A third pin PD3 connects to a contact B terminal of the
power supply selection switch 24. A fourth pin PD4 and a fifth pin
PD5 connect to an internal circuit 56 of the digital camera 10,
and are used as data transfer lines. A movable armature terminal
24C of the power supply selection switch 24 connects to a DC/DC
converter 58, and a power supply voltage applied to the movable
armature terminal 24C is converted to a required voltage by the
DC/DC converter 58 and then supplied to the internal circuit 56.
[0042] A first pin PC1 of the connector 44 in the mobile phone
40 connects to the ground (GND). A second pin PC2 connects to a
contact C terminal of the power supply selection switch 48. A third
pin PC3 connects to a cathode of the battery 42 and a contact D
terminal of the power supply selection switch 48. A fourth pin PC4
and a fifth pin PC5 connect to an internal circuit 60 of the mobile
phone 40, and are used as data transfer lines. A movable armature
terminal 48E of the power supply selection switch 48 connects to
a DC/DC converter 62, and a power supply voltage applied to the
movable armature terminal 48E is converted to a required voltage
by the DC/DC converter 62 and then supplied to the internal circuit
60.
[0043] The digital camera 10 and the mobile phone 40 are connected
using the multi-conductor connection cable 50 to provide connections
between the pins with the same numbers. When the power supply selection
switch 24 of the digital camera 10 is set to A, and the power supply
selection switch 48 of the mobile phone 40 is set to C, power is
supplied from the battery 26 of the digital camera 10 to the mobile
phone 40. At this time, the battery 42 of the mobile phone 40 is
detached.
[0044] When the power supply selection switch 24 of the digital
camera 10 is set to B, and the power supply selection switch 48
of the mobile phone 40 is set to D, power is supplied from the battery
42 of the mobile phone 40 to the digital camera 10. At this time,
the battery 26 of the digital camera 10 is detached.
[0045] When the power supply selection switch 24 of the digital
camera 10 is set to B, and the power supply selection switch 48
of the mobile phone 40 is set to C, both batteries 26, 42 are detached.
When the power supply selection switch 24 of the digital camera
10 is set to A, and the power supply selection switch 48 of the
mobile phone 40 is set to D, power of the digital camera 10 is supplied
from the battery 26, and power of the mobile phone 40 is supplied
from the battery 42.
[0046] Thus, any combinations of settings of the power supply selection
switches 24, 48 do not cause electrical connection between the batteries
26, 42. If the batteries 26, 42 were electrically connected, a short
would be caused with a risk of destruction or fire. To avoid such
a risk, it is necessary that any setting states of the power supply
selection switches 24, 48 do not cause direct connection between
the batteries 26, 42.
[0047] In FIGS. 1 and 2, the power supply selection switches 24,
48 are mechanical switches, but instead, switches using a semiconductor
may be used. Further, power supplying paths may be switched by setting
from the menu screen displayed on the liquid crystal monitor 18
or the liquid crystal display unit 46.
[0048] FIG. 3 shows a circuit of essential portions according to
another embodiment. In FIG. 3, similar parts as in FIG. 2 are denoted
by the same reference numerals, and descriptions thereof are omitted.
In FIG. 3, a detection switch 66 (SW3) is added which detects a
power supply source in the digital camera 10. The detection switch
66 and the power supply selection switch 24 are interlocking switches,
and the detection switch 66 is used for detecting whether the digital
camera 10 receives power supplied from an outside (mobile phone
40). One contact E terminal of the detection switch 66 connects
to an output terminal of the DC/DC converter 58 via a resistance
R1, and the other contact F terminal of the detection switch 66
connects to the ground. When the power supply selection switch 24
is set to B (that is, the digital camera 10 receives the power supplied
from the battery 42 of the mobile phone 40), a movable armature
of the detection switch 66 contacts the contact F terminal, and
a movable armature terminal 66G connects to the ground. Thus, an
L (Low) signal as a detected signal is input to the internal circuit
56.
[0049] On the other hand, when the power supply selection switch
24 is set to A, the movable armature of the detection switch 66
connects to the contact E terminal, and an output voltage Vcc of
the DC/DC converter 58 is applied to the movable armature terminal
66G. Thus, an H (High) signal as a detected signal is input to the
internal circuit 56.
[0050] The detection switch 66 is provided in order to detect the
state where the power is supplied from the mobile phone 40 to the
digital camera 10. Generally, power consumption of the digital camera
10 is higher than that of the mobile phone 40, and the battery 26
of the digital camera 10 has a capacity about twice as high as that
of the battery 42 of the mobile phone 40. Thus, the state where
the power is supplied from the mobile phone 40 to the digital camera
10 places a heavy current load on the battery 42 of the mobile phone
40, causing a problem of significant reduction in a power supply
voltage, or the like.
[0051] In this embodiment, when the state where the power is supplied
from the mobile phone 40 to the digital camera 10 is detected, control
is performed to simultaneously operate to reduce the power consumption
of the digital camera 10 (move to a lower power consumption mode).
For example, (1) an operation of the liquid crystal monitor 18 is
stopped (backlight OFF), (2) charging to a flash circuit is stopped,
and (3) a clock operation frequency in the camera is reduced. These
controls achieve reduction in power consumption.
[0052] When the above described state is detected, the data transfer
lines (fourth pin and fifth pin) of the connection cable 50 are
used to generate a command to reduce power, from the digital camera
10 to the mobile phone 40. The mobile phone 40 receives the command,
and is automatically set to a mode of reducing power consumption
(low power consumption mode), or controlled to turn off the power
supply of the mobile phone 40. Thus, it is preferable to reduce
the power consumption of the mobile phone 40 and concentrate the
power of the battery 42 on the digital camera 10.
[0053] FIG. 4 is a block diagram of internal configurations of
the digital camera 10 and the mobile phone 40 shown in FIG. 3. The
battery 42 mounted to the mobile phone 40 connects to the power
supply selection switch 48 (SW2), and connects to the power supply
selection switch 24 (SW1) of the digital camera 10 via the connection
cable 50. Likewise, the battery 26 mounted to the digital camera
10 connects to the power supply selection switch 24, and connects
to the power supply selection switch 48 of the mobile phone 40 via
the connection cable 50.
[0054] As described above, the connections of the batteries 26,
42 as the power supply sources are switched by the power supply
selection switches 24, 48. The voltage of the battery 26 or the
battery 42 selected by the power supply selection switch 48 of the
mobile phone 40 is applied to a power supply unit 68 in the mobile
phone 40. The power supply unit 68 is a block including the DC/DC
converter 62 illustrated in FIG. 3, and a battery voltage applied
to the power supply unit 68 shown in FIG. 4 is converted to a required
voltage by the power supply unit 68 and then supplied to a signal
processing circuit 70 and other blocks. The signal processing circuit
70 is a circuit block such as a voice signal processing circuit,
which performs various processings necessary for the function of
the mobile phone.
[0055] The mobile phone 40 includes an external interface 71 for
communication with the digital camera 10 and other external devices,
and a microprocessing unit (MPU) 72 as a control unit.
[0056] On the other hand, the digital camera 10 includes an external
interface 81 for communication with the mobile phone 40 and other
external devices, and a microprocessing unit (MPU) 82 as a camera
control unit. The external interfaces 71, 81 correspond to the connectors
44, 28 illustrated in FIG. 1. As the external interfaces 71, 81,
various interfaces can be applied such as a serial port, USB, IrDA,
IEEE 1394, or other serial interfaces or parallel interfaces.
[0057] The MPU 82 of the digital camera 10 shown in FIG. 4 controls,
based on instruction signals from the mode selection switch 19 and
various operating units 84, operations of corresponding circuits,
display on the liquid crystal monitor 18, flash firing, auto focus
(AF), automatic exposure (AE), image-capturing operation, recording
processing, or the like. A block of the operating unit 84 includes
various operation keys such as the shutter-release button 12, the
cross button 21, the menu/enter button 22, or the cancel button
23 illustrated in FIG. 1.
[0058] As shown in FIG. 4, the voltage of the battery 26 or the
battery 42 selected by the power supply selection switch 24 of the
digital camera 10 is applied to a power supply unit 85 in the camera.
The power supply unit 85 is a block including the DC/DC converter
58 illustrated in FIG. 3. The battery voltage applied to the power
supply unit 85 shown in FIG. 4 is converted to a required voltage
by the power supply unit 85 and then supplied to each circuit block
via power supply control switches SW11, SW12, SW13, SW14, SW15,
SW16 and SW17 (hereinafter referred to as the power supply control
switches SW11 to SW17).
[0059] The detected signal of the detection switch 66 interlocked
with the power supply selection switch 24 is input to the MPU 82,
and the MPU 82 distinguishes between the battery 26 and the battery
42 as the power supply source based on the detected signal received.
When detecting the state where the power is supplied from the battery
42 of the mobile phone 40, the MPU 82 monitors a voltage value of
the battery 42. Thus, the MPU 82 controls operations of the power
supply control switches SW 11 to SW 17, and a frequency dividing
ratio of a frequency divider circuit 86, based on the detected signal
from the detection switch 66 and information on the voltage value
of the battery 42 (voltage a).
[0060] The power supply switch SW 11 is a switch for selecting
supply or interruption (ON/OFF) of power to display system circuits
including the liquid crystal monitor 18 and an LCD controller 88.
The power supply switch SW12 is a switch for selecting supply or
interruption of power to a flash circuit 89. The flash circuit 89
is a block including a condenser, a charging circuit, a firing control
circuit, or the like. The power supply switch SW 13 is a switch
for selecting supply or interruption of power to image pickup system
circuits including an image pickup device 90 and an image pickup
signal processing circuit 91. The power supply switch SW14 is a
switch for selecting supply or interruption of power to a picture
signal generating circuit 94 for outputting a picture signal to
an image output unit (video terminal) 93. The power supply switch
SW15 is a switch for selecting supply or interruption of power to
a voice input unit including a voice input unit (microphone) 96
and a voice signal processing circuit 97. The power supply switch
SW16 is a switch for selecting supply or interruption of power to
a voice output circuit 100 for outputting voice from a voice output
unit (speaker) 99. The power supply switch SW17 is a switch for
selecting supply or interruption of power to a digital signal processor
(DSP) 102.
[0061] The frequency divider circuit 86 is a circuit which switches
the frequency dividing ratio to 1/1, 1/2, 1/4, 1/8, 1/16, . . .
by a control signal from the MPU 82, and provides the DSP 102 with
a clock signal obtained by frequency dividing a clock signal from
a crystal oscillator 104 by a designated frequency dividing ratio.
[0062] Operations of the digital camera 10 will be outlined below.
A light having passed through a taking lens 106 is subjected to
light amount adjustment by a shutter and aperture mechanism 108,
and then enters the image pickup device 90. As the image pickup
device 90, various devices such as a CCD image sensor or a CMOS
image sensor can be applied. Many photosensors are arranged on a
light-receiving surface of the image pickup device 90 in two dimensions,
and a subject image focused on the light-receiving surface is converted
to signal charge of amount corresponding to the amount of entering
light by each photosensor.
[0063] The signal charge accumulated in each photosensor of the
image pickup device 90 is successively read out as voltage signals
(image signals) in accordance with the signal charge based on pulses
provided from an unshown drive circuit, and sent to the image pickup
signal processing circuit 91. The image pickup signal processing
circuit 91 includes an analog signal processing circuit such as
a sampling hold circuit, a color separation circuit, a gain control
circuit, and an A/D converter. In the image pickup signal processing
circuit 91, the voltage signals are subjected to correlation double
sampling (CDS), color separation into color signals of R, G, B,
and gain control of a level of each color signal, and then converted
to digital signals by the A/D converter.
[0064] Digital image signals output from the image pickup signal
processing circuit 91 are sent to the DSP 102. The DSP 102 is a
signal processing block having image signal processing units such
as a luminance/color-difference signal generation circuit, a gamma
correction circuit, a sharpness correction circuit, a white balance
correction circuit, and various signal processing unit such as a
compression/decompression processing unit, a filing processing unit,
an encryption/decoding processing unit, a memory control unit, a
recording/reproducing processing unit. Image data sent from the
image pickup signal processing circuit 91 to the DSP 102 is converted
to luminance signals (Y signals) and color-difference signals (Cr,
Cb signals) in the DSP 102, and subjected to a predetermined processing
such as gamma correction, then stored in an internal memory 110.
[0065] When the captured image is to be displayed and output, the
image data is read from the internal memory 110, and converted to
picture signals in a predetermined display format via the DSP 102.
The picture signals thus obtained are output to the liquid crystal
monitor 18 via the LCD controller 88. The image data in the internal
memory 110 is rewritten at regular intervals by the image signals
captured from the image pickup device 90, and the picture signals
generated from the image data are fed to the liquid crystal monitor
18, thus causing the liquid crystal monitor 18 to display a captured
picture (live image). It is possible to transfer this picture to
the mobile phone 40 and display it on the liquid crystal display
unit 46 of the mobile phone 40.
[0066] Pressing the shutter-release button 12 in the operating
unit 84 causes an instruction signal to start image-capturing to
be generated. The MPU 82 detects the instruction signal and performs
an image pickup operation for recording. Specifically, the MPU 82
performs various calculations such as focus evaluation calculation
or AE calculation from the image data captured in response to "half
press (S1=ON)" of the shutter-release button 12, controls an
unshown lens driving unit based on the calculation results to move
the taking lens 106 to a focusing position, while controls the shutter
and aperture mechanism 108, and controls charge accumulation time
of the image pickup device 90.
[0067] The MPU 82 controls the image pickup system circuit in response
to receiving the image-capturing start signal by "full press
(S2=ON)" of the shutter-release button 12, starts capturing
the image data for recording, and sends a command to the compression/decompression
circuit in the DSP 102. Thus, the compression/decompression circuit
compresses the image data in the internal memory 110 in JPEG or
other predetermined formats. The compressed image data is recorded
in the memory card 14 mounted to the memory card socket 112.
[0068] When a reproduction mode is selected by the mode selection
switch 19, the image data is read from the memory card 14, and the
read image data is decompressed by the compression/decompression
circuit in the DSP 102, then reproduced and output on the liquid
crystal monitor 18. It is also possible to transfer the image stored
in the memory card 14 to the mobile phone 40, and send it to an
outside by an e-mail sending function of the mobile phone 40.
[0069] The operations of the digital camera 10 thus configured
will be described. FIG. 5 is a flowchart of a control procedure
of the digital camera 10 of this embodiment. When the power supply
switch 17 of the camera is operated to turn on the power supply
(Step S510), the MPU 82 first determines whether the camera is in
a power supply switching state (the state where the camera receives
the power supplied from the mobile phone 40), based on the detected
signal from the detection switch 66 (Step S512). When the power
supply source is the battery 26 of the digital camera 10 (when determined
NO), the process goes to Step S514, and all the power supply control
switches SW11 to SW17 are turned on.
[0070] On the other hand, in Step S512, when determined that the
camera receives the power supplied from the battery 42 of the mobile
phone 40 (when determined YES), the process goes to Step S520. In
Step S520, the power supply switch SW17 is turned on and other power
supply switches SW11 to SW16 are OFF. Next, the voltage value (voltage
a) of the battery 42 is read to determine whether the voltage a
is below a determination reference value a1 previously defined (Step
S522). The determination reference value a1 is defined as a voltage
sufficient to operate the digital camera 10 by supplying power from
the battery 42, and set as a lower limit voltage such that the voltage
value decreases below the determination reference value a1 to cause
irregular operation of the camera.
[0071] In Step S522, when determined that the voltage a is below
the determination reference value a1 (when determined YES), the
process goes to Step S524, and the frequency dividing ratio is lowered
by one step, then the process returns to Step 522. Lowering the
clock frequency dividing ratio by one step reduces power consumption
to increase the voltage a.
[0072] In Step S522, when determined that the voltage a is above
the determination reference value a1 (when determined NO), the process
goes to Step S530. In step S530, it is determined whether the camera
is set to the image-capturing mode. This determination is made based
on a setting state of the mode selection switch 19. When the image-capturing
mode is selected (when determined YES), the power supply switch
SW 13 is turned on for allowing image-capturing (Step S532).
[0073] On the other hand, in Step S530, when determined NO (when
the reproduction mode or other operation mode without image-capturing
is selected), the power supply switch SW13 is turned off to control
to prevent supplying power to the image pickup system circuit (Step
S534). After Step S532 or Step S534, the process returns to Step
S522. Then, operations of the operation keys are monitored to perform
operations in accordance with operation instructions.
[0074] The digital camera 10 and the mobile phone 40 according
to this embodiment are configured to share both batteries 26, 42,
so that even if one battery is drained, power is supplied from the
other battery to allow use of the device. This allows the device
to be used for longer hours.
[0075] The above described power supply selection switches (SW1,
SW2) are manually operated by users, but the power supply selection
switches may be electronic switches that automatically control switching
the power supplies. FIG. 6 shows a control procedure thereof.
[0076] After the power supply of the digital camera 10 is turned
on (Step S610), the voltage of the battery 26 is input to an A/D
conversion port of the MPU 82 and measured (Step S612). It is determined
whether the measured voltage value is above the defined voltage
(Step S614). If the voltage is above the defined voltage, there
is no need to supply power from the outside, so that the power supply
selection switch SW1 in the digital camera 10 remains set to A (Step
S616).
[0077] On the other hand, when the voltage does not reach the defined
voltage in Step S614, it is determined that power needs to be supplied
from the outside, and the power supply selection switch SW1 is switched
to B (Step S620). Then, a control signal indicating a switching
state of the power supply (power supply switching control signal)
is sent to the mobile phone 40 (Step S622) to enter a power saving
operation mode (Step S624). At this time, the MPU 72 of the mobile
phone 40 sets the power supply selection switch SW2 to D, and sets
the mobile phone 40 to the power saving operation mode, based on
the power supply switching control signal sent from the digital
camera 10. Thus, the power is supplied from the battery 42 of the
mobile phone 40 to the digital camera 10.
[0078] After Step S616 or Step S624, the process goes to Step S630.
In Step S630, a timer counter is started, and when a count value
reaches a defined value, the process returns to step S612. Thus,
the above described switching determination processing of the power
supply is repeated in a given cycle.
[0079] In FIG. 6, the controls of the digital camera 10 are described,
but the same applies to the mobile phone 40. The MPU 72 of the mobile
phone 40 monitors the voltage of the battery 42, and when determined
that the battery 42 does not reach a defined voltage, the MPU 72
switches connection of the power supply selection switch 48 to C,
and controls such that the mobile phone 40 receives the power supplied
from the battery 26 of the digital camera 10. Then, the MPU 72 sends
a control signal indicating a switching state of the power supply
(power supply switching control signal) to the digital camera 10.
[0080] Next, a modification of the embodiment will be described.
FIGS. 7 and 8 show circuits of essential portions according to another
embodiment of the invention. In the drawings, identical or similar
parts as in FIG. 2 are denoted by the same reference numerals, and
descriptions thereof are omitted. In the embodiment shown in FIGS.
7 and 8, a connector 28 of a digital camera 10 is shared as a connecting
unit of a remote control device 200.
[0081] As a device which automatically distinguishes between a
state where a mobile phone 40 is connected to the digital camera
10 (FIG. 7) and a state where the remote control device 200 is connected
to the digital camera 10 (FIG. 8), a detection pin PDk is provided
in the connector 28. A detection signal line of the detection pin
PDk connects to a Vcc output terminal of a DC/DC converter 58 via
a pull-up resistance R2, and a detected signal is input to an internal
circuit 56 of the digital camera 10.
[0082] A connector 44 of the mobile phone 40 is also provided with
a detection pin PCk, and the detection pin PCk has no connection
in the mobile phone 40 (non-connected terminal). Thus, when the
digital camera 10 and the mobile phone 40 are connected via a connection
cable 50 as shown in FIG. 7, the detected signal of the detection
pin PDk becomes an "H (high)" signal.
[0083] On the other hand, a detection pin PRk provided in a connector
210 of the remote control device 200 shown in FIG. 8 connects to
the ground in the remote control device 200. Thus, when the digital
camera 10 and the remote control device 200 are connected via the
connection cable 50, the detection pin PDk connects to the ground,
and the detected signal becomes an "L (low)" signal.
[0084] The digital camera 10 determines that the remote control
device 200 is connected thereto when the detected signal is "L",
while determines that the mobile phone 40 is connected thereto,
or that there is no connection, when the detected signal is "H".
To distinguish between the connecting state and the non-connecting
state of the mobile phone 40, a communication signal is output from
the digital camera 10 to distinguish between them according to presence
or absence of a reply.
[0085] A first pin PR1 of the connector 210 in the remote control
device 200 connects to the ground (GND) together with the detection
pin PRk. A second pin PR2 corresponds to a power input terminal,
and connects to a DC/DC converter 212 in the remote control device
200. A third pin PR3 is a non-connected terminal. A fourth pin PR4
and the fifth pin PR5 connect to an internal circuit 214 and are
used as data transfer lines.
[0086] A power supply voltage applied to the second pin PR2 is
converted to a required voltage by the DC/DC converter 212 and then
supplied to the internal circuit 214. When an operating unit 216
provided in the remote control device 200 is operated, a command
signal in accordance with the operation is transferred to the digital
camera 10 via the data transfer lines (fourth pin and fifth pin).
The digital camera 10 operates in accordance with the command signal
received from the remote control device 200. This achieves remote
control of the digital camera 10 using the remote control device.
[0087] As described above, according to the invention, the digital
camera connectable to the mobile electronic device can receive the
power necessary to operate the camera from the battery of the external
mobile electronic device to be connected, so that even if the battery
of the digital camera is drained, switching to the battery of the
electronic device allows the digital camera to be used for longer
hours.
[0088] According to another aspect of the invention, the power
can be supplied from the battery of the digital camera to the external
mobile electronic device, so that even if the battery of the mobile
electronic device is drained, switching to the battery of the digital
camera allows the mobile electronic device to be used for longer
hours.
[0089] It should be understood, however, that there is no intention
to limit the invention to the specific forms disclosed, but on the
contrary, the invention is to cover all modifications, alternate
constructions and equivalents falling within the spirit and scope
of the invention as expressed in the appended claims. |