Digital Camera Patent Abstract
This patent discloses a digital camera and an external device for
both storing digital images from the camera and controlling certain
camera functions. The external device may be either directly attached
to the camera or remotely attached by way of a cable or similar
device. The external device may also include a means for recording
images onto removable recording media. The external device may also
include a button for sending instructions to the camera to allow
for switching between image resolution modes, flash lighting modes,
and autofocusing modes. Digital Camera Patent Claims
What is claimed is:
1. An external storage device connectable to a digital camera by
a cable, said digital camera including a first memory for storing
image data, a second memory for storing image data converted from
the image data in said first memory by a predetermined resolution
and a third memory including a program for controlling said image-data-conversion
by said predetermined resolution, comprising: a hand-held size housing
that can accommodate a recording medium; a single copy button provided
on said housing; an LCD provided on said housing; and a control
section, wherein, when said copy button is pushed once, said control
section sends a first request to said digital camera for information
about whether image data exists within said second memory, when
said digital camera sends back the information indicating that there
is image data within said second memory in response to said first
request to said control section, said control section sends a second
request to said digital camera requesting transmission of the image
data within said second memory to said recording medium, when said
digital camera sends back the information indicating that there
is no image data within said second memory in response to said first
request, said control section sends a third request to said digital
camera requesting information about said predetermined resolution
set in said third memory, when said digital camera sends back the
information regarding the predetermined resolution set in said third
memory to said control section, said LCD displays the information
regarding the predetermined resolution, when said copy button is
pushed within the period that said LCD displays the information
regarding the predetermined resolution, said control section sends
a fourth request to said digital camera requesting the resolution
set in said third memory be changed, thereby copy and resolution
change actions are achieved by using said single copy button, and
said external device is in a hand-held size.
2. An external device according to claim 1, in which all of the
buttons on said housing consist of: said copy button; a power button
operable to supply power to said control section; and an erase button
operable to erase said recording medium.
3. A system comprising said external device and said digital camera
as defined in claim 1.
Digital Camera Patent Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a digital camera such as electronic
still camera, an external storage device for externally storing
the image data within this digital camera, and a system made of
them, and, in particular, to an external storage device which can
set operational functions of the digital camera from the outside.
2. Related Background Art
Electronic still camera is an apparatus which captures an image
of a subject by using a solid-state imaging device such as CCD.
An analog signal output from the solid-state imaging device is AD-converted
and, after being subjected to a predetermined processing, stored
in a main memory within the electronic still camera. The main memory
is constituted by a semiconductor non-volatile memory such as E.sup.2
PROM.
SUMMARY OF THE INVENTION
The number of E.sup.2 PROMs which can be installed within an electronic
still camera, however, is restricted by the size of the housing
of the camera. Accordingly, in order to record or keep a larger
number of images, external storage devices which are to be connected
to the electronic still camera by way of a cable have been developed.
While the conventional external storage device has only a function
of recording and reproducing image data, functional setting of the
camera is effected on the camera side. In an electronic still camera
using an LCD, information about functional settings of the camera
is displayed on the LCD, so as to provide users with necessary information.
Nevertheless, as various kinds of information are displayed on the
same LCD attached to the electronic still camera, it is difficult
for users who are not accustomed to electronic instruments to discern
such information.
The present invention relates to a digital camera such as electronic
still camera, an external storage device connected to this digital
camera by way of a cable or the like, and a system made of them.
The digital camera in accordance with the present invention comprises
a solid-state imaging device which captures an image of a subject;
a first storage device which stores, selectively with a first or
second resolution, image data of the subject output from the solid-state
imaging device; a second storage device which stores a program including
an instruction for switching, according to an order from outside
of the digital camera, the resolution of the image data stored in
the first storage device; a first control section which executes
the program stored in the second storage device; and a terminal
to which the order from the outside is input.
An external storage device connected to the terminal of this digital
camera comprises a housing; a liquid crystal display attached to
one side face of the housing; and a second control section which
orders, by way of the terminal, the digital camera to rewrite the
instruction and causes the liquid crystal display to show information
about the resolution of the digital camera.
Further, in a system constituted by a digital camera and an external
storage device, the digital camera comprises a first housing; a
solid-state imaging device which is disposed within the first housing
and captures an image of a subject; a first storage device which
is disposed within the first housing and temporarily stores image
data of the subject; a second storage device which is disposed within
the first housing; and a first control section which is disposed
within the first housing, reads out the image data stored in the
first storage device, and converts the image data according a predetermined
instruction so as to write thus converted data into the second storage
device. Also, this external storage device comprises a second housing
having an opening into which a recording medium to store the image
data is inserted; a terminal attached to the second housing; and
a second control section which is disposed within the second housing,
reads out, by way of the terminal, the image data stored in the
second storage device of the digital camera, writes thus read-out
data into the recording medium, and transmits a control signal for
changing the predetermined instruction to the first control section
of the digital camera by way of the terminal.
The present invention will be more fully understood from the detailed
description given hereinbelow and the accompanying drawings, which
are given by way of illustration only and are not to be considered
as limiting the present invention.
Further scope of applicability of the present invention will become
apparent from the detailed description given hereinafter. However,
it should be understood that the detailed description and specific
examples, while indicating preferred embodiments of the invention,
are given by way of illustration only, since various changes and
modifications within the spirit and scope of the invention will
be apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of an external storage device;
FIG. 2 is an explanatory view of a camera system constituted by
an external storage device and a digital camera;
FIG. 3 is a block diagram showing a configuration of a camera system;
FIG. 4 is an explanatory view for explaining an indicator on a
liquid crystal display;
FIG. 5 is an explanatory view for explaining an indicator on the
liquid crystal display;
FIG. 6 is an explanatory view for explaining an indicator on the
liquid crystal display;
FIG. 7 is an explanatory view for explaining an indicator on the
liquid crystal display; and
FIGS. 8 to 10 are flow charts for explaining operations of an external
storage device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following, embodiments of the present invention will be
explained. In the following explanation, constituents identical
to each other will be referred to with marks identical to each other,
without their overlapping explanations repeated.
FIG. 1 is a plan view of an external storage device OM. An end
portion of a housing 1 forms a battery box 2. When a battery is
placed within this battery box 2, and a power switch button 3 is
then pushed down, the external storage device OM is actuated, thereby
lighting a liquid crystal display (LCD) 4 attached to the same face
of the housing 1 on which the button 3 is located. The LCD 4 shows
the numbers of photographed shots within a camera and within a memory
card (recording medium) 5, whether or not the recording medium is
attached, the battery voltage, and the like. FIG. 1 shows a state
where the LCD 4 is totally lighted. In the following explanation,
the face of the housing 1 on which the LCD 4 is disposed will be
referred to as upper face.
At the front face of the housing 1, disposed is an opening 5a through
which the memory card 5 is inserted into the front face of the housing
1 in parallel thereto. When pushed into the housing 1 by way of
this opening 5a, the memory card 5 is stabilized with respect to
the housing 1. At the front face of the housing 1, disposed is an
eject button 6 which is protruded in a direction in parallel to
the upper face of the housing 1. When the eject button 6 is urged
toward the inside of the housing 1, the locking mechanism of the
memory card 5 which has been inserted into the housing 1 is released,
so that the memory card 5 can be taken out from the inside of the
housing 1.
As will be explained later, the memory card 5 stores image data
within a digital camera to which the external storage device OM
is connected. The external storage device OM is connected to the
digital camera by way of a terminal 7. When a copy switch button
8 is pushed down, the image data within the digital camera can be
transferred into the memory card 5. Also, when an erase switch button
9 is pushed down, the image data stored within the memory card 5
are erased.
FIG. 2 shows a camera system constituted by a digital camera CA
and the external storage device OM. The terminal 7 of the external
storage device OM is connected to the digital camera CA by way of
a cable 10. Here, the digital camera CA and the external storage
device OM are connected to each other through a serial interface.
The digital camera CA comprises a finder 11, a photographing lens
12, and a shutter release button 13 which are attached to a housing
25, as well as a storage device therewithin which stores image data
of a subject which has formed an image incident on the inside of
the digital camera CA by way of the photographing lens 12.
FIG. 3 is a block diagram showing a camera system constituted by
the digital camera CA and the external storage device OM.
The digital camera CA is controlled by a control unit 14 constituted
by a main board. Namely, the control unit 14 is a microcomputer
unit comprising a central processing unit (CPU) 15, which is a control
section for executing an operation, and a read-only memory (ROM)
16 which stores a program used at the time when the CPU is actuated
and the like. Namely, the control section 15 executes the program
written into the ROM 16. The unit is actuated when a switch SW is
turned on so as to supply an electric power from a power circuit
24 to the main board 14.
Light reflected by a subject S is transmitted through the photographing
lens 12 so that it can be made incident on a single-plate color
CCD image sensor 17. Namely, the subject S forms an image on a light-receiving
surface of the image sensor 17. Here, the image sensor 17 includes
a CCD (solid-state imaging device), which comprises a plurality
of pixels arranged two-dimensionally, and a circuit for applying
a transfer clock to each pixel. As the CCD, that used for VTR is
employed.
A CCD output signal from the image sensor 17 is converted into
a video signal by a front-end circuit 18 including an amplifier
circuit and a sample holding circuit, and thus obtained video signal
is converted into a quantized digital signal by an AD converter
19.
The video signal is directly AD-converted by the AD converter 19
and stored in a frame memory (storage device) 20 which can accumulate
image data for at least one picture. The frame memory 20 is controlled
by the control unit 14. The frame memory 20 is a so-called PSRAM.
which apparently functions as static random access memory (SRAM).
A main memory 21 is also disposed within the housing 25. The main
memory 21 is a non-volatile memory which enables both readout and
writing and, more specifically, is an electrically erasable programmable
ROM (E.sup.2 PROM) which can erase the voltage at its floating gate
when a voltage is applied to its control gate.
The image data temporarily stored in the frame memory 20 are written
into the main memory (storage device) 21 according to an order from
the control section 15. Namely, according to the instruction stored
within the ROM 16, the control section 15 reads out the image data
stored in the frame memory 20, converts thus read-out image data,
and writes thus converted data into the main memory 21. This writing
operation has two modes. One of them is a high-resolution mode in
which high-resolution image data temporarily stored in the frame
memory 20 are read out and all of thus read-out data are written
into the main memory 21. The other is a low-resolution mode in which
the high-resolution image data temporarily stored in the frame memory
20 are read out and then thus read-out image data are written into
the main memory 21, while a part thereof is skipped, such that the
amount of data becomes 1/2 of the high-resolution image data. Namely,
under the low-resolution mode, image data twice as large as those
of the high-resolution image data can be stored in the same capacity
(available space) of memory. These modes can be switched therebetween
as the instruction within the ROM 16 is rewritten according to an
order from the external storage device OM. Namely, the program stored
within the ROM 16 of the digital camera CA includes an instruction
for setting the operational outline of the system, and this instruction
further includes therewithin an instruction for switching, according
to the order from the outside of the digital camera, the resolutions
of the image data to be stored in the main memory 21. Here, at the
time of this writing operation, the image data stored in the frame
memory may be written into the main memory as being compressed.
The image data stored in the main memory 21 are copied or transferred
to the recording medium 5 within the external storage device OM
by way of a transmitting and receiving circuit 23 of the digital
camera CA and a transmitting and receiving circuit 26 of the external
storage device OM. The image data being transmitted are temporarily
accumulated in a communication buffer 22 from the main memory 21
by the control section 15, and then sequentially transferred to
the transmitting circuit 23, from which they are transferred to
the external storage device OM by way of terminals 29 and 7. The
data being received are temporarily stored in the communication
buffer 22 by way of the receiving circuit 23 and then sequentially
read out by the control section 15.
The external storage device OM is controlled by a control section
27a which is a CPU or the like. The instruction to be executed by
the control section 27a is stored in a ROM 27b. In FIG. 3, an operating
section CP is assumed to include the buttons 8 and 9 in FIG. 1.
FIGS. 8 to 10 are flow charts for explaining operations of the
control section 27a in the external storage device OM. The control
section 27a performs operations shown in these flow charts by executing
a program including a plurality of instructions written in the ROM
27b.
When the power switch button 3 is pushed down (step 1 (S1)), an
electric power is supplied from a power circuit 28 to the control
section 27a and the like, whereby the device is actuated on the
basis of the program stored in the ROM 27b of this device.
When the memory card 5 is placed within a cavity 5b of the external
storage device, a non-depicted sensor detects information about
the existence of the memory card 5. This sensor is connected to
the control section 27a, which judges whether the memory card 5
is placed within the cavity 5b or not (step 2 (S2)). When it is
judged that the memory card 5 is not inserted, the control section
27a causes the display 4 to show information about the nonexistence
of the memory card 5 as "NO CARD" (step 11 (S11)). Here,
when it is judged that the memory card 5 is inserted, the control
section 27a causes the display 4 to show a card icon 4a depicted
in FIG. 4.
The control section 27a judges whether the external storage device
OM is connected to the digital camera OM or not (step 3 (S3)). Specifically,
this judgment is effected as it is judged whether the terminal 7
of the external storage device OM is connected to the terminal 29
of the digital camera CA or not. When it is judged that the external
storage device OM is not connected to the digital camera CA, the
control section 27a causes the display 4 to show information about
this unconnected state as "NO CON" (step 12 (S12)).
When it is judged that the external storage device OM is connected
to the digital camera CA, the control section 27a detects the available
space on the memory card 5 (step 4 (S4)). Then, the control section
27a causes the display 4 to show information about thus detected
available space on the memory card 5 in terms of percent as depicted
by an indicator 4b of FIG. 4 (step 5 (S5)).
Further, the control section 27a detects the number of image data
files within the memory card 5 (step 6 (S6)). Then, the control
section 27a causes the display 4 to show information about thus
detected number of image data files as depicted by an indicator
4c of FIG. 4 (step 7 (S7)). Also, the control section 27a judges
the battery voltage and causes the display 4 to show information
about the battery voltage as depicted by an icon 4d of FIG. 4. When
the battery voltage is sufficient for driving the external storage
device OM, regions 4e and 4f are lighted. When the battery voltage
is insufficient for continuously driving the external storage device
OM for at least 30 minutes, the region 4e of the icon 4d is not
lighted while the region 4f is lighted. Also, when the battery voltage
is insufficient for driving the external storage device OM, the
icon 4d is not lighted.
Namely, according to orders from the control section 27a, the display
4 indicates information about image data within the memory card
5, information about the battery voltage, and the like.
More specifically, in the state where no image data are stored
in the digital camera CA, when the external storage device OM and
the digital camera CA are connected to each other by way of the
cable 10 and both their power supplies are turned on, information
depicted in FIG. 4 is shown on the LCD 4. Namely, the upper region
4b of the LCD 4 indicates the capacity recordable within the memory
card 5 in terms of %, while its lower region 4c displays the recorded
image data within the memory card 5 in terms of the number of shots.
Since no image data are stored within the memory card 5, the upper
region 4b and lower region 4c of the LCD 4 show characters of 100%
and 0, respectively.
Then, the control section 27a judges whether the all-erase button
9 is pushed down or not (step 8 (S8)). When it is judged that the
all-erase button 9 is pushed, the control section 27a erases the
data within the memory card 5 (step 13 (S13)).
When it is judged that the all-erase button 9 is not pushed, the
control section 27a judges whether the copy button 8 is pushed or
not (step 9 (S9)).
When it is judged that the copy button 8 is not pushed, the control
section 27a judges whether the power button 3 is pushed or not (step
10 (S10)). When it is judged that the power button 3 is pushed,
the control section 27a stops supplying the electric power from
a non-depicted battery (step 14 (S14)).
When it is judged that the power button 3 is not pushed, the control
section 27a judges whether or not 90 seconds have passed without
any button being pushed (step 15 (S15)). When it is judged that
90 seconds have passed without any button being pushed, the control
section 27a stops supplying the electric power from the non-depicted
battery (step 14 (S14)). When it is judged that 90 seconds have
not passed without any button being pushed, the control section
27a re-executes the instruction of step 2 (S2).
In the case where the copy button 3 is pushed at step 9 (S9), the
control section 27a transmits, to the digital camera CA, a command
requesting information about whether the main memory 21 in the digital
camera CA contains image data or not (step 100 (S100)). Thus transmitted
command is detected at the control section 15 by way of the transmitting
circuit 23 and the communication buffer 22. The control section
15 is operated by the program including the instruction written
in the ROM 16. When the control section 15 of the digital camera
CA receives the above-mentioned command, it detects the information
about whether image data exist within the main memory 21 or not,
and transmits thus detected information to the external storage
device OM. Accordingly, the control section 27a of the external
storage device OM receives the information about whether image data
exist within the digital camera CA or not (step 101 (S101)).
From thus received information, the control section 27a judges
whether image data exist within the digital camera CA or not (step
102 (S102)). When it is judged that image data exist within the
digital camera CA, the control section 27a transmits, to the control
section 15 of the digital camera CA, a command requesting transmission
of the image data within the main memory 21 (step 103 (S103)). Receiving
this request for transmitting the image data, the control section
15 of the digital camera CA transmits the image data within the
main memory 21 to the control section 27a of the external storage
device OM. Receiving the image data (step S104 (S104)), the control
section 27a writes thus received image data into the memory card
5 (step 105 (S105)). In other words, the control section 27a stores
the memory card 5 with the image data transmitted to the control
section 27a from the main memory 21 of the digital camera CA.
Namely, in the state where image data are stored in the digital
camera CA, when the external storage device OM and the digital camera
CA are connected to each other by way of the cable 10, and the copy
button 8 in the operating section CP is then pushed down, the control
section 27a of the external storage device OM transmits a control
signal corresponding to copying, by way of the transmitting and
receiving circuits 26 and 23, to the communication buffer 22. The
control section 15 of the digital camera CA detects the control
signal transferred to the communication buffer 22, and the instruction
for the copying mode is executed in response to this control signal.
The instruction for the copying mode is also stored within the
ROM 16. In the copying mode, the control section 15 reads out the
image data within the main memory 21, temporarily stores thus read-out
data together with control codes such as header and trailer including
a flag sequence added thereto, and transfers thus stored data to
the external storage device OM by way of the transmitting and receiving
circuit 23. While performing error check of thus transmitted data,
the transmitting and receiving circuit 26 of the external storage
device OM receives the data. The control section 27a reads out thus
received data and writes the read-out data into the memory card
5. Here, as mentioned above, the image data stored within the memory
card 5 can be erased when the all-erase button 9 in the operating
section CP is pushed down.
In the following, an operation for changing the resolution of the
digital camera effected by the external storage device OM will be
explained. Though the following explanation relates to an example
where the photographing mode of the digital camera is changed from
a high resolution mode allowing 8 shots to be photographed to a
low resolution mode allowing 16 shots to be photographed, the reverse
change can be effected in a similar manner.
When it is judged at step 102 (S102) that no image data exist within
the main memory 21, the control section 27a transmits, to the digital
camera CA, a command requesting information about resolution (step
200 (S200)). It takes about 0.5 second for the digital camera CA
to respond to this command. Accordingly, the control section 27a
causes the display 4 to show an arrow mark such as that depicted
in FIG. 5 for one second (step 201 (S201)).
Receiving the command for requesting the resolution information,
the control section 15 of the digital camera CA transmits the resolution
information (whether the resolution is high or low) to the control
section 27a of the external storage device OM. Accordingly, the
control section 27a receives the resolution information from the
digital camera CA (step 202 (S202)). Receiving the resolution information
from the digital camera CA, the control section 27a causes the display
4 to show thus received resolution information as depicted in FIG.
6 (step 203 (S203)).
More specifically, in the state where no image data exist within
the main memory 21, when the copy button 8 is pushed down, the information
in FIG. 5 is lighted for about one second in the LCD 4, and then
the information in FIG. 6 is displayed there. Namely, in this state,
when the copy button 8 of the operating section CP is pushed down
(step 9 (S9)), the control section 27a of the external storage device
OM transmits a control signal corresponding to an operation for
inspecting the state of the main memory 21 to the communication
buffer 22 by way of the transmitting and receiving circuits 26 and
23 (step 200 (S200)). The control section 15 of the digital camera
CA detects the control signal transferred to the communication buffer
22 and transmits, to the control section 27a of the external storage
device OM, information about the photographing mode which has already
been set within the ROM 16 in response to this control signal. Receiving
this photographing mode (high-resolution mode) information (step
202 (S202)), the control section 27a of the external storage device
OM causes the LCD 4 to show this information (step 203 (S203)).
The control section 27a of the external storage device OM judges
whether the copy button 8 is pushed down or not (step 204 (S204)).
When it is judged that the copy button 8 is not pushed, the control
section 27a judges whether 10 seconds have passed after step 203
(S203). When it is judged that 10 seconds have not passed after
step 203 (S203), the control section 27a repeats the operation of
step 204 (S204); whereas, when it is judged that 10 seconds have
passed, the control section 27a repeats the operation of step 2
(S2).
Namely, the LCD 4 shows this resolution information for a predetermined
period (10 seconds) as depicted in FIG. 6 (step 203 (S203)). During
this display period, when the copy switch 8 is continuously pushed
down, as noted above, the control section 27a of the external storage
device OM transmits, to the digital camera CA, a control signal
for changing the setting of the resolution within the ROM 16 of
the digital camera CA (step 205 (S205)). The control section 15
of the digital camera CA receiving this signal changes the photographing
mode (function mode) within the ROM 16 from the high resolution
to the low resolution, detects whether the photographing mode is
changed or not, and, after confirming that the photographing mode
has been changed, transmits thus confirmed information to the control
section 27a of the external storage device OM. When the control
section 27a of the external storage device OM receives this information
(step 206 (S206)), it causes the LCD 4 to show the information about
this change as depicted in FIG. 7 (step 207 (S207)). This display
is effected for three seconds with flickering. Thereafter, the LCD
4 shows the information in FIG. 4 again.
Thus, as the functional setting of the digital camera CA is performed
by the external storage device OM, the number of parts such as switches
in the main body of the digital camera CA can be reduced, thereby
lowering the manufacturing cost of the digital camera CA. Also,
as such functional setting of the digital camera CA is effected
not by a large host computer but by an external storage device having
a size which can be held with one hand, the convenience for its
user can be remarkably improved.
As explained in the foregoing, when the functional setting of the
digital camera is effected by the external storage device separated
from the digital camera, a quite convenient digital camera can be
provided. Here, while modes of resolution are switched by the external
storage device OM as the photographing mode in the foregoing embodiments;
photographing modes such as flash lighting modes (strobe lighting
mode and single lighting mode) and autofocus modes (spot autofocus,
multi-autofocus, and macro-autofocus) of the digital camera may
also be switched by the external storage device OM.
From the invention thus described, it will be obvious that the
invention may be varied in many ways. Such variations are not to
be regarded as a departure from the spirit and scope of the invention,
and all such modifications as would be obvious to one skilled in
the art are intended to be included within the scope of the following
claims.
The basic Japanese Application No. 33852/1996 filed on Feb. 21,
1996 is hereby incorporated by reference. |