Digital Camera Patent Abstract
A digital camera with an anti-blur function is provided with simple
structures. The digital camera comprises an automatic exposure control
mechanism for an automatic exposure mode and inclinometer. As sub-modes,
the automatic exposure mode comprises a normal program mode and
a high-shutter-speed priority program mode. Output of the inclinometer
is repeatedly checked at a predetermined period to detect camera-shake.
Camera-shake is determined by stable or unstable output from the
inclinometer. When the output is unstable, it is determined that
camera-shake exists, and the high-shutter-speed priority program
mode is selected. Contrarily, when it is stable, it is determined
that no camera-shake exists, and the normal program mode is selected.
Attitude of the camera, which is sensed by the inclinometer, is
recorded to a detachable PC card with the image data when camera-shake
is not detected. If camera-shake is detected, the sensed attitude
data is invalidated. Digital Camera Patent Claims
What is claimed is:
1. A digital camera comprising: an automatic exposure control mechanism
that operates in an automatic exposure mode which comprises at least
two sub-modes including a normal program mode and a high-shutter-speed
priority program mode, wherein said high-shutter-speed priority
program mode selects a higher shutter speed in comparison with said
normal program mode under a same photographing condition; a camera
attitude sensing processor that senses an attitude of said camera
with respect to the vertical; a camera-shake detecting processor
that detects a camera-shake in accordance with a stability of said
attitude, sensed by said camera attitude sensing processor; a selecting
control processor that selects said high-shutter-speed priority
program mode as said sub-mode, when said attitude, sensed by said
camera attitude sensing processor, is unstable and said camera-shake
is detected by said camera-shake detecting processor while said
automatic exposure mode is performed; wherein said camera attitude
sensing processor comprises an inclinometer, and said selecting
control processor repeatedly checks output from said inclinometer
at a predetermined period and invalidates attitude information about
said attitude detected while photographing if said output corresponding
to said attitude is unstable while said automatic exposure mode
is performed.
2. A camera according to claim 1 that comprises a recording processor
which records in a recording medium, said attitude information about
said attitude detected while photographing, together with image
data corresponding to an image taken during said photographing and
wherein said selecting control processor invalidates said attitude
information when said attitude, sensed by said camera attitude sensing
processor, is unstable and said camera-shake is detected by said
camera-shake detecting processor while said automatic exposure mode
is performed.
3. A camera according to claim 1, wherein said selecting control
processor selects said normal program mode as said sub-mode, when
said attitude sensed by said camera attitude sensing processor is
stable and said camera-shake is not detected, while said automatic
exposure mode is performed.
4. A camera according to claim 1, wherein said selecting control
processor switches selection of said sub-mode from said high-shutter-speed
priority program mode to said normal program mode when status of
said attitude sensed by said camera attitude sensing processor changes
from unstable to stable and said camera-shake is no longer detected,
while said automatic exposure mode is performed.
5. A digital camera comprising: an automatic exposure control mechanism
that operates in an automatic exposure mode which comprises at least
two sub-modes including a normal program mode and a high-shutter-speed
priority program mode, wherein said high-shutter-speed priority
program mode selects a higher shutter speed in comparison with said
normal program mode under a same photographing condition; a camera
attitude sensing processor that senses an attitude of said camera
with respect to the vertical; a camera-shake detecting processor
that detects a camera-shake in accordance with a stability of said
attitude, sensed by said camera attitude sensing processor; a selecting
control processor that selects said high-shutter-speed priority
program mode as said sub-mode, when said attitude, sensed by said
camera attitude sensing processor, is unstable and said camera-shake
is detected by said camera-shake detecting processor while said
automatic exposure mode is performed; and a recording processor
which records in a recording medium, attitude information about
said attitude detected while photographing, together with image
data corresponding to an image taken during said photographing and
wherein said selecting control processor invalidates said attitude
information when said attitude, sensed by said camera attitude sensing
processor, is unstable and said camera-shake is detected by said
camera-shake detecting processor while said automatic exposure mode
is performed.
Digital Camera Patent Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a digital camera.
2. Description of the Related Art
In a digital camera that is capable of recording an image and reproducing
a recorded image, a camera is known that detects an attitude of
the camera body from the vertical (which may be classified as the
lateral (see FIG. 17) and longitudinal (see FIG. 16) positions of
the camera body). In a recording mode, the above digital camera
includes attitude information about the camera body with the image
data. In the playback mode the recorded image may be reproduced
and displayed on a monitor of the camera in a direction suitable
for watching as a playback image. Namely, the topside of the monitor
and the top side of the playback image (original subject image)
are made almost identical.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a digital camera
with a simple structure which includes an inclinometer to sense
camera body attitude from the vertical and is able to prevent blurring
induced by camera-shake.
According to the present invention, a digital camera is provided
with an anti-blur function. The digital camera comprises an automatic
exposure control mechanism, a camera attitude sensing processor,
a camera-shake detecting processor and a selecting control processor.
The automatic exposure control mechanism is performed in an automatic
exposure mode. The automatic exposure mode comprises at least two
sub-modes, such as a normal program mode and high-shutter-speed
priority program mode. The high-shutter-speed priority program mode
selects higher shutter speeds when compared to the normal program
mode under the same photographing conditions. The camera attitude
sensing processor senses an attitude of the camera from the vertical.
The camera-shake detecting processor detects camera-shake in accordance
with stability of the camera attitude. While the automatic exposure
mode is performed, the selecting control processor selects the high-shutter-speed
priority program mode when the attitude of the camera is unstable,
and camera-shake is detected by the camera-shake detecting processor.
On the other hand, while the automatic exposure mode is selected,
the selecting control processor may select the normal program mode
when attitude of the camera is stable and no camera-shake is detected.
The digital camera preferably comprises a recording processor.
Together with image data of a photographed image, the recording
processor records attitude information in a recording medium, which
corresponds to the attitude of the camera when the photograph is
taken. While the automatic exposure mode is performed, the selecting
control processor invalidates the attitude information when the
attitude of the camera is unstable, and camera-shake is detected
by the camera-shake detecting processor.
Further, while the automatic exposure mode is performed, the selecting
control processor may switch selection of the sub-mode from the
high-shutter-speed priority program mode to the normal program mode
when the status of attitude sensed by the camera attitude sensing
processor changes from unstable to stable, and no further camera-shake
is detected.
Preferably, the camera attitude sensing processor comprises an
inclinometer and the selecting control processor repeatedly checks
output from the inclinometer at a predetermined period. If the output
which corresponds to the attitude of the camera is unstable while
the automatic exposure mode is performed, the attitude infomation
is invalidated.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and advantages of the present invention will be better
understood from the following description, with reference to the
accompanying drawings in which:
FIG. 1 is an electric schematic of a digital camera of an embodiment
to which the present invention is applied;
FIG. 2 is an Automatic Exposure (AE) chart representing the program
of an automatic exposure mode of the digital camera;
FIG. 3 is a perspective view from the backside of the digital camera;
FIG. 4 illustrates a structure of an inclinometer mounted on the
digital camera of the present embodiment by indicating an inside
state of the inclinometer when a photographing lens of the digital
camera is trained vertically upward or downward;
FIG. 5 illustrates the structure of the inclinometer mounted on
the digital camera of the present embodiment by indicating an inside
state of the inclinometer when the digital camera is disposed in
the upside-down position;
FIG. 6 illustrates structure of the inclinometer mounted on the
digital camera of the present embodiment by indicating an inside
state of the inclinometer when the digital camera is disposed in
the first longitudinal position;
FIG. 7 illustrates the structure of the inclinometer mounted on
the digital camera of the present embodiment by indicating an inside
state of the inclinometer when the digital camera is disposed in
the second longitudinal position;
FIG. 8 illustrates the structure of the inclinometer mounted on
the digital camera of the present embodiment by indicating an inside
state of the inclinometer when the digital camera is disposed in
the regular or lateral position;
FIG. 9 illustrates electrical structure of switches in the inclinometer,
which are comprised of a metallic ball and four conductive elements
as shown in FIGS. 4 through 8;
FIG. 10 illustrates the electrical interconnection between terminals
of the system controller and the switches shown in FIG. 9;
FIG. 11 is a timing chart of a sensing operation at the system
controller for sensing the ON/OFF state of the switches in the inclinometer.
FIG. 12 is a flowchart of the control routine, which relates to
the present embodiment, and is executed in the digital camera;
FIG. 13 is a flowchart of the control routine in a recording mode;
FIG. 14 is a flowchart of the control routine in a playback mode;
FIG. 15 is a flowchart of the control routine when the automatic
exposure mode is selected;
FIG. 16 illustrates a photographing operation with the digital
camera disposed in a longitudinal position; and
FIG. 17 illustrates the digital camera disposed in the regular
or lateral position, and displaying a reproduced image that was
photographed in the longitudinal position of FIG. 16, on a monitor
mounted on the digital camera.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is described below with reference to embodiments
shown in the drawings.
FIG. 3 is a perspective view of a digital camera of the present
embodiment, which is applied to the present invention. A photographing
lens 14 is provided on a front side of a camera body 12 of the digital
camera 10, and on the upper surface of the camera body 12 is a release
button 16 and an LCD panel 17. On the LCD panel 17, various information
concerning the operational status of the camera, photographing,
and so on, are indicated.
Further, a laterally long rectangular LCD monitor 18 is provided
for the digital camera 10, on about the center of the backside of
the camera body 12. The LCD monitor 18 is a color display monitor.
In the recording mode, live video of a subject to be monitored through
the photographing lens 14 is displayed on the LCD monitor 18. In
the playback mode a captured image is displayed on the LCD monitor
18.
Furthermore, on the backside of the camera body 12, disposed around
the LCD monitor 18, a viewfinder 20, mode dial 22 and function buttons
24, are provided. When a power switch (not shown) of the digital
camera 10 is in `ON` state, the recording mode and playback mode
can be selected by revolving the mode dial 22.
An AE (automatic exposure) control mechanism is mounted on the
digital camera 10, and by operating the function buttons 24, either
a manual exposure mode or AE (automatic exposure) mode can be selected.
As sub-modes of the AE mode, either a normal program mode (normal
automatic exposure type) or high-shutter-speed priority program
mode (high shutter speed priority automatic exposure type) can be
selected. In the high-shutter-speed priority program mode, a relatively
fast shutter speed is automatically selected, compared to the shutter
speed selected in the normal program mode with the same conditions.
FIG. 2 is a programmed AE chart of the AE mode. A broken line A
indicates a programmed AE line for the normal program mode, and
a solid line B indicates the line for the high-shutter-speed priority
program mode.
An inclinometer 50 (refer FIGS. 4-8) is provided for the digital
camera 10 to sense an attitude of the camera body 12 against the
vertical, which may correspond to a lateral or longitudinal position
of the camera body 10. In the recording mode of the digital camera
10, attitude information of the camera body 12, sensed by the inclinometer
50 during a photographing operation, is recorded along with the
image data to a memory in an IC card, such as a PC card 39. In the
playback mode, the playback image is displayed on the LCD monitor
18 in accordance with the attitude information, which is recorded
in the memory, so that the topside of the playback image and the
camera body 12 are parallel.
For example, when a subject S is photographed with the camera body
12 held in the longitudinal position, as shown in FIG. 16, and the
image data obtained by the above is reproduced in the playback mode,
the image of the subject S is displayed on the LCD monitor 18 in
such manner that the topside of the image and the substantial topside
of the camera body 12 are substantially identical, as shown in FIG.
17.
FIG. 1 is an electrical schematic of the digital camera 10. A system
controller 30 which comprises a microcomputer, is provided to the
digital camera 10, and generally controls the digital camera 10.
A photometric sensor 31, release switch 32 connected with the release
button 16, switch group 33 including switches connected with the
function buttons 24, the LCD panel 17, LCD monitor 18 and inclinometer
50 are connected to the system controller 30. Further, an aperture
15, shutter 19, CCD 34, analog signal processor 35, A/D converter
36, digital signal processor 37 and PC card controller 38 are connected
to the system controller 30.
When the release button 16 is depressed, the system controller
30 derives the subject brightness via the photometric sensor 31.
At this moment, a subject image formed on the surface of the CCD
34, through the photographing lens 14, is converted to electrical
signals by the CCD 34. The electrical signals are then digitalized
via the analog signal processor 35 and the A/D converter 36, and
input to the digital signal processor 37. In the digital processor
37, a predetermined process is applied to the digitalized signals
and image data is generated. This image data is recorded to the
PC card 39, which has a built-in non-volatile memory, such as a
flash memory (recording medium), for example.
The PC card 39 is connected with the digital processor 37 via the
PC card controller 38. The digital processor 37 can record image
data of a captured image to the PC card 39 via the PC card controller
38. Further, the digital processor 37 can transfer image data recorded
in the PC card 39 to the buffer memory 40 via the PC card controller
38.
In the playback mode, image data is transferred from the PC card
39 to the buffer memory 40 via the digital signal processor 37.
In the recording mode, monitoring video (moving video) of the subject
image formed on the surface of the CCD 34 is input to the digital
signal processor 37 from the A/D converter 36. The image data in
each of the recording and playback mode, are output to the LCD monitor
18, and displayed on the LCD monitor as playback images.
A description of the inclinometer 50, which senses the attitude
of the camera body 12 is given as follows with reference to FIGS.
4 through 8. The inclinometer 50 is fixed on a printed circuit board
48 (refer FIG. 3) disposed inside the camera body 12, so that top,
bottom, right and left side in each figure (FIG. 4 to FIG. 8) correspond
to those of the camera body 12 described in FIG. 3. A first conductive
element 51, second conductive element 52, third conductive element
53 and fourth conductive element 54 are arranged in the inclinometer
50, as shown in each of FIGS. 4 to 8. A conductive bulb or a metallic
ball 55 which is at least has a surface comprised of conductive
material, is provided inside the space surrounded by the first through
fourth conductive elements. Each conductive element 51-54 is connected
to the system controller 30.
When the digital camera 10 is disposed in the lateral position
(as shown in FIG. 17), which is a regular position, the metallic
ball 55 is settled in the position shown in FIG. 8. As a result,
the third conductive element 53 and the fourth conductive element
54 are electrically connected together. When the digital camera
10 is disposed in the first longitudinal position (which is achieved
by rotating the camera body 12, 90 degrees clockwise around the
optical axis of the photographing lens from the regular or lateral
position, as shown in FIG. 16), the metallic ball 55 is settled
in the position shown in FIG. 6. As a result, the second conductive
element 52 and the fourth conductive element 54 are electrically
connected together.
When the digital camera 10 is disposed in the second longitudinal
position (which is achieved by rotating the camera body 12, 90 degrees
counterclockwise around the optical axis of the photographing lens
from the lateral position), the metallic ball 55 is settled in the
position shown in FIG. 7. As a result, the first conductive element
51 and the third conductive element 53 are electrically connected
together. When the digital camera 10 is disposed in the upside-down
position which is contrary to the above regular lateral position,
the metallic ball 55 is settled in the position shown in FIG. 5.
As a result, the first conductive element 51 and the second conductive
element 52 are electrically connected together. Further, when the
photographing lens 14 of the digital camera 10 is trained vertically
up or down, the metallic ball 55 settles in a neutral position where
the metallic ball 55 is apart from all the conductive elements as
shown in FIG. 4. As a result, none of the conductive elements 51-54
are electrically connected.
Namely, as shown in FIG. 9, the inclinometer 50 consists of a first
switch SW1 comprised of the first and third conductive elements
51, 53, a second switch SW2 comprised of the first and second conductive
elements 51, 52, a third switch SW3 comprised of the second and
fourth conductive elements 52, 54, and a fourth switch SW4 comprised
of the third and fourth conductive elements 53, 54. Each of the
four switches SW1-SW4 is individually closed (switched on) when
the metallic ball 55 contacts the respective pair of conductive
elements, and open (switched off) when the metallic ball 55 is apart
from the conductive elements.
The system controller 30 has four input/output terminals 1, 2,
3 and 4. The first conductive element 51 is connected with terminal
1, the second conductive element 52 with terminal 2, the third conductive
element 53 with terminal 3, and the fourth conductive element 54
with terminal 4. FIG. 10 illustrates the connection between terminals
1-4 of the system controller 30 and the first through fourth switches
SW1-SW4 of the inclinometer 50.
A timing chart shown in FIG. 11 indicates an example of a sensing
operation at the system controller 30 that senses the ON/OFF state
of each switch SW1-SW4 in the inclinometer 50. In this example,
the system controller 30 regularly feeds a first pulse signal 61
from terminal 2 to the second conductive element 52, and simultaneously
feeds a second pulse signal 62 from terminal 3 to the third conductive
element 53. Due to the connection between the switches SW1-SW4 and
terminals 1-4, as described in FIG. 10, the first pulse signal 61
from terminal 2 is fed to terminal 1 when the switch SW2 is ON,
and when the switch SW3 is ON, it is fed to terminal 4. Further,
the second pulse signal 62 from terminal 3 is fed to terminal 1
when the switch SW1 is ON, and when the switch SW4 is ON, it is
fed to terminal 4.
Therefore, the system controller 30 monitors both input signals
from terminals 1 and 4. When the system controller detects the first
pulse signal 61 applied to terminal 2, in terminal 1, it determines
that the switch SW2, which corresponds to the upside-down position,
is ON. When the system controller 30 detects the first pulse signal
61 applied to terminal 2, in terminal 4, it determines that the
switch SW3, which corresponds to the first longitudinal position,
is ON. When the system controller 30 detects the second pulse signal
62 applied to terminal 3, in terminal 1, it determines that the
switch SW1, which corresponds to the second longitudinal position,
is ON. When the system controller 30 detects the second pulse signal
62 applied to terminal 3, in terminal 4, it determines that the
switch SW4, which corresponds to the regular lateral position, is
ON.
FIG. 12 is a flowchart of a control process, relating to the present
invention, which is executed by the system controller 30. This control
process starts when the power switch of the camera 10 is switched
on. First of all, the system controller is initialized, and counters
C1 through C4, the operation of which are described hereinafter,
are reset (Step S1). Subsequently, the selection of the mode dial
22 is checked (Step S3). Then, a determination is made as to whether
the PC card 39 is set or not. When it is determined that the PC
card 39 is set, the recording mode selection is checked (Step S5,
S7). Contrarily, when the PC card 39 is not set, the control proceeds
to Step S25.
When the recording mode is selected, an interrupt caused by an
interval timer is enabled (Step S11). Further, an interrupt caused
by a playback trigger is disabled and an interrupt caused by a recording
trigger is enabled (Step S13 and S15). Subsequently, the control
routine returns to Step S3. NOTE: the interrupt, playback triggers
and recording triggers are described hereinafter. On the other hand,
at Step S7, when it is determined that the recording mode is not
selected, a determination is made as to whether the playback mode
is selected (Step S17).
If the playback mode is selected, interrupt caused by the interval
timer is disabled (Step S19). And then, interrupt caused by the
recording trigger is disabled and interrupt caused by the playback
trigger is enabled (Step S21 and S23). Subsequently, the control
returns to Step S3. On the other hand, at Step S17, when it is determined
that the playback mode is not selected, interrupt caused by the
interval timer, recording trigger and playback trigger is disabled
(Step S25, S27 and S29), and the control routine returns to Step
S3.
FIG. 13 is a flowchart of a control routine process (an interrupt
handling) in the recording mode. This control routine process starts
when the release switch 32 is switched on (which corresponds to
a recording trigger), when the release button 16 is depressed, while
the recording mode is selected. The control routine begins with
photometry by the photometric sensor 31, and then a determination
is made as to whether or not the normal program mode is selected
(Step S31 and S33). When the normal program mode is selected, combination
of f-number and shutter speed is selected in accordance with the
programmed AE line for the normal program mode, as indicated by
the broken line A in FIG. 2 (Step S35). And then, the aperture and
exposure (shutter speed) are controlled in accordance with the selected
combination (Step S37 and S39), so that a subject image is formed
on the surface of the CCD 34 and is converted to image data.
The image data obtained by the above process is recorded by the
memory provided in the PC card 39 (Step S41). Subsequently, validity
of the attitude information for the camera body 12, which is sensed
by the inclinometer 50 during an image capturing operation, is checked
(Step S43). If the attitude information is valid, the attitude information
is recorded in the memory of the PC card 39, together with the data
of the captured image (Step S45). This interrupt handling then ends
and the control returns to the main routine. If the attitude information
is invalid, this interrupt handling ends immediately, and the control
returns to the main routine without executing Step S45.
When it is determined at Step S33 that the normal program mode
is not selected, a combination of f-number and shutter speed is
selected in accordance with the programmed AE line of the high-shutter-speed
priority program mode which is indicated by the solid line B in
FIG. 2 (Step S47). The control then reverts to Step S37 and the
process continues as previously described i.e., the aperture and
exposure (shutter speed) are controlled in accordance with the selected
combination (Step S37 and S39), so that a subject image formed on
the surface of the CCD 34 is converted to image data, and the Steps
41-45, as described above, are then executed.
FIG. 14 is a flowchart of a control routine process (an interrupt
handling) in the playback mode. This control process starts when
the release switch 32 is switched on (which corresponds to a playback
trigger) by the operation of the release button 16, when the playback
mode is selected. First of all, a check is made to see whether a
recorded image is being displayed on the LCD monitor 18 (Step S51).
If no image is currently being replayed on the LCD monitor 18, image
data recorded in the PC card 39 is transferred to the buffer memory
40 (Step S53), and the transferred image data is fed to the LCD
monitor 18, so that the reproduced or playback image is displayed
on the LCD monitor 18 (Step S55). The control process in this interrupt
handling then returns to the main routine. Contrarily, when it is
determined at Step S51 that a recorded image is reproduced and currently
being replayed on the LCD monitor 18, output of image data to the
LCD monitor 18 is suspended (Step S57).
FIG. 15 is a flowchart of a control routine in the AE mode which
may be comprised of a normal and high-speed-shutter program mode.
This routine is an interrupt handling by the interval timer, and
it is periodically repeated while the AE mode is selected.
In the control-flow including this routine, signals from the inclinometer
50 are cyclically checked at a predetermined period while the AE
mode is selected. If the signals from the inclinometer 50 are stable,
the normal program mode is selected and the exposure is controlled
by the normal program mode. On the other hand, if the output from
the inclinometer 50 is unstable, the high-speed-shutter program
mode is selected and the exposure is controlled by the high-speed-shutter
program mode. Although the attitude (the lateral or longitudinal
position) of the camera body 10 is generally fixed, the metallic
ball 55 in the inclinometer 50 moves about with camera movement.
This situation occurs when the camera is operated in a moving car
for example, and the image is blurred. When the camera or inclinometer
50 is shaken, the metallic ball 55 bounds about the space within
the inclinometer 50 and one of the first through fourth switches
SW1-SW4 is alternately switched between the ON and OFF states. When
alternation between the ON and OFF states is repeated rapidly, the
attitude information is invalidated and treated as void.
The inclinometer 50, which uses contact of a conductive or metallic
ball between conductive elements, is originally utilized for detecting
the attitude of the camera. However the inclinometer 50 can also
be utilized to determine camera-shake by detecting rapid alternate
switching between the ON and OFF states, by one of the first to
fourth switches SW1-SW4. Therefore, in a camera 10 to which an embodiment
of the present invention is applied, the inclinometer 50 is utilized
not only for detecting the attitude of the camera but also for detecting
camera-shake. When the detected camera-shake exceeds a predetermined
rapidity, the high-shutter-speed priority program mode is selected
and the automatic exposure mechanism is controlled by the high-shutter-speed
priority program, so that blurring of the photographed image is
prevented.
Selection between the normal program mode or the high-shutter-speed
program mode is described as follows with reference to FIG. 15.
Firstly, whether the first switch SW1 is ON or not, is checked
(Step S61). If the first switch SW1 is ON, the counter C1 is incremented
by one (Step S63), and each counter C2, C3 and C4 is reset (Step
S65). The control then proceeds to Step S67.
If it is determined at Step S61 that the first switch SW1 of the
inclinometer 50 is OFF, whether the second switch SW2 is ON, is
checked at Step S69. If the second switch SW2 is ON, the counter
C2 is incremented by one, and each counter C1, C3 and C4 is reset
(Step S69, S71 and S73) and the control proceeds to Step 67.
If it is determined at Step S69 that the second switch SW2 of the
inclinometer 50 is OFF, whether the third switch SW3 is ON, is checked
at Step S75. If the third switch SW3 is ON, the counter C3 is incremented
by one, and each counter C1, C2 and C4 is reset (Step S75, S77 and
S79). Subsequently, the control proceeds to Step 67.
If it is determined at Step S75 that the third switch SW3 of the
inclinometer 50 is OFF, whether the fourth switch SW4 is ON, is
checked at Step S81. If the fourth switch SW4 is ON, the counter
C4 is incremented by one, and each counter C1, C2 and C3 is reset
(Step S81, S83 and S85) and the control proceeds to Step 67. If
it is determined at Step 81 that the fourth switch SW4 of the inclinometer
50 is OFF, namely, when every first to fourth switch SW1-SW4 is
OFF, each of the counters C1, C2, C3 and C4 is reset concurrently
(Step 81 and 87), and the control proceeds to Step S67.
At Step S67, a determination is made as to whether the counter
C1 exceeds a predetermined value A (e.g. A=3). If the counter C1
exceeds the predetermined value A (i.e. when C1 is 4 or more when
A=3), the attitude information of the camera body 12, which is sensed
by the inclinometer 50 while photographing, is validated and the
sub-mode of the AE mode is set to the normal program mode (Step
S89 and S91). The control process in this interrupt handling then
ends and returns to the main routine.
When it is determined at S67 that the counter C1 is below the predetermined
value A, a determination is then made as to whether the counter
C2 exceeds the predetermined value A (Step S93). If the counter
C2 exceeds the predetermined value A, the attitude information of
the camera body 12, which is sensed by the inclinometer 50 while
photographing, is validated and the sub-mode of the AE mode is set
to the normal program mode (Step S93, S89 and S91). The control
of this interrupt handling then ends and returns to the main routine.
When it is determined at S93 that the counter C2 is below the predetermined
value A, a determination is then made as to whether the counter
C3 exceeds the predetermined value A (Step S95). If the counter
C3 exceeds the predetermined value A, the attitude information of
the camera body 12, which is sensed by the inclinometer 50 while
photographing, is validated and the sub-mode of the AE mode is set
to the normal program mode (Step S95, S89 and S91). The control
in this interrupt handling then ends and returns to the main routine.
When it is determined at S95 that the counter C3 is below the predetermined
value A, a determination is then made as to whether the counter
C4 exceeds the predetermined value A (Step S95 and S97). If the
counter C4 exceeds the predetermined value A, the attitude information
of the camera body 12, which is sensed by the inclinometer 50 while
photographing, is validated and the sub-mode of the AE mode is set
to the normal program mode (Step S97, S89 and S91). The control
in this interrupt handling then ends and returns to the main routine.
When it is determined at S97 that the counter C4 is below the predetermined
value A, namely, when every counter C1-C4 is below the predetermined
value A, the attitude information of the camera body 12, which is
sensed by the inclinometer 50 while photographing, is invalidated
and the sub-mode of the AE mode is set to the high-shutter-speed
priority program mode (Step S97, S99 and S101). The control in this
interrupt handling then ends and returns to the main routine.
As described above, at Step S67, S93, S95 and S97, it is determined
whether any of the counters C1 through C4 exceed the predetermined
value A. The control-flow shown in FIG. 15 is repeated at a predetermined
period, thus if one of the counters C1-C4 exceed the predetermined
value A, it can be determined that the metallic ball 55 has kept
one of the switches SW1-SW4 in an ON state for a certain period.
Consequently, it can be regarded that camera-shake did not exceed
a predetermined value for the above certain period. Namely, if one
of the counters C1-C4 exceed the predetermined value A, it is determined
that the camera has been stable for the above certain period, which
is defined by the predetermined value A, and the normal program
mode is selected as the sub-mode of the AE mode. Contrarily, if
none of the counters C1-C4 exceed the predetermined value A, it
is then determined that the camera is unstable (namely, the camera
10 is shaking), and the high-shutter-speed priority program mode
is selected as the sub-mode of the AE mode. Consequently, image
blur is prevented.
Although the embodiments of the present invention have been described
herein with reference to the accompanying drawings, obviously many
modifications and changes may be made by those skilled in this art
without departing from the scope of the invention.
The present disclosure relates to subject matter contained in Japanese
Patent Application No. 2000-023522 (filed on Feb. 1, 2000) which
is expressly incorporated herein, by reference, in their entireties.
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