Digital Camera Patent Abstract
A digital camera having a camera body which includes a main surface
and a lens surface substantially orthogonal to the main surface,
a photographic lens of a photographic optical system positioned
on the lense surface, and an optical viewfinder unit rotatably attached
to the main surface such that the optical viewfinder unit is rotatable
to a position substantially orthogonal to the main surface of the
camera body and in a plane substantially parallel to said lens surface.
An operation unit is positioned in the camera body such that operations
buttons are arranged on the main surface of the camera body and,
when the optical viewfinder unit is in a closed position, the operation
buttons are substantially covered to protect against unintentional
operation. Digital Camera Patent Claims
What is claimed as new and desired to be secure by Letters Patent
of the United States is:
1. A digital camera comprising: a camera body having a main surface
and a lens surface substantially orthogonal to said main surface;
a photographic lens of a photographic optical system, said photographic
lens positioned on said lens surface; a solid state imaging device
coupled to said photographic optical system; an operation unit arranged
on said main surface and having a release button and a control feature
of the digital camera; and an optical viewfinder unit rotatably
attached to said camera body such that said optical viewfinder unit
is rotatable from a closed position wherein said viewfinder unit
is substantially in planar contact with said main surface, to an
open position wherein the viewfinder unit is substantially orthogonal
to said main surface and in a plane substantially parallel to said
lens surface, wherein when said optical viewfinder unit is in said
closed position, said release button and control feature are covered
and protected by said optical viewfinder unit.
2. The digital camera as claimed in claim 1, wherein said optical
viewfinder unit comprises a planar structure having a rectangle
shaped optical viewfinder window which serves as a field frame for
defining a range of an object image.
3. The digital camera as claimed in claim 2, wherein said optical
viewfinder window includes an opening defined by said field frame.
4. The digital camera as claimed in claim 2, wherein said main
surface comprises first and second opposing edges and said optical
viewfinder unit is rotatably attached to said main surface at an
axis parallel to and in the vicinity of said second edge; and a
length and width of said optical viewfinder window are set according
to a field angle of said photographic lens and a width of said camera
body defined by a distance from said first edge to said second edge
of said main surface.
5. The digital camera as claimed in claim 4, further comprising
a view plate rotatably attached to said main surface at an axis
in the vicinity of said first edge such that said view plate is
moveable to a position substantially orthogonal to said main surface
and substantially parallel to the surface of the optical viewfinder
window, said view plate having a hole positioned such that a center
of the hole is substantially in line with an orthogonal line extending
from a center of the optical viewfinder window.
6. The digital camera as claimed in claim 5, wherein said hole
in said view plate has a diameter in a range of about 4 mm to about
7 mm.
7. The digital camera as claimed in claim 1, wherein said optical
viewfinder unit comprises: a planar structure having a rectangle
shaped optical viewfinder window; at least one transparent member
positioned in said optical viewfinder window; and a pattern of marks
printed on said at least one transparent member and configured to
assist a user of the digital camera in defining a photographing
range of an object image.
8. The digital camera as claimed in claim 7, wherein said at least
one transparent member comprises a single transparent member having
a predetermined thickness; and said pattern of marks comprises a
pair of corresponding marks one corresponding mark printed on each
of opposing sides of said transparent member such that the pair
of corresponding marks are overlain as viewed by the user of the
digital camera when an object image is in photographing range of
the camera.
9. The digital camera as claimed in claim 8, wherein a position
of said corresponding marks is determined according to the thickness
of the transparent member and a field angle of a photographing lens
of the photographic optical system.
10. The digital camera as claimed in claim 9, wherein each corresponding
mark comprises opposing frame lines each respective frame line being
parallel to sides of the transparent optical viewfinder window.
11. The digital camera as claimed in claim 9, wherein each corresponding
mark comprises a frame rectangle the sides of which are parallel
to respective sides of the optical viewfinder window.
12. The digital camera as claimed in claim 9, wherein each corresponding
mark comprises a set of shapes printed in a vicinity of each comer
of said optical viewfinder window.
13. The digital camera as claimed in claim 12, wherein said shapes
in said set of shapes include at least one of an L-shape and a circle.
14. The digital camera as claimed in claim 8, wherein said transparent
member is made of a transparent material selected from a group consisting
of glass and plastic.
15. The digital camera as claimed in claim 7, wherein said at least
one transparent member comprises two or more transparent members
which are spaced apart from each other a predetermined distance;
and said pattern of marks comprises a group of corresponding marks
one corresponding mark printed on a surface of each transparent
member such that the group of corresponding marks are overlain as
viewed by the user of the digital camera when an object image is
in photographing range of the camera.
16. The digital camera as claimed in claim 15, wherein a position
of said corresponding marks is determined according to the distance
between said transparent members and a field angle of a photographing
lens of the photographic optical system.
17. The digital camera as claimed in claim 16, wherein each corresponding
mark comprises opposing frame lines each respective frame line being
parallel to sides of the transparent optical viewfinder window.
18. The digital camera as claimed in claim 16, wherein each corresponding
mark comprises a frame rectangle the sides of which are parallel
to respective sides of the optical viewfinder window.
19. The digital camera as claimed in claim 16, wherein each corresponding
mark comprises a set of shapes printed in a vicinity of each corner
of said optical viewfinder window.
20. The digital camera as claimed in claim 19, wherein said shapes
in said set of shapes include at least one of an L-shape and a circle.
21. The digital camera as claimed in claim 15, wherein said transparent
members are each made of a transparent material selected from a
group consisting of glass and plastic.
22. The digital camera as claimed in claim 1, wherein said camera
body comprises a rectangular solid of about 60 mm length.times.about
40 mm width.times.about 15 mm height.
23. The digital camera of claim 1, wherein said control feature
of the digital camera comprises at least one of a photograph button,
a display unit, and a transmission button.
24. A digital camera comprising: means for containing optical and
electrical systems of said camera, said means for containing having
a main surface and an edge surface substantially orthogonal to said
main surface; a photographic lens of said optical system, said photographic
lens exposed to an exterior of said means for containing through
said edge surface; a solid state imaging device coupled to said
optical system; means for executing a photographing operation and
controlling features of said digital camera; means for finding a
view of an object image; and means for moving said means for finding
a view of an object from a closed position substantially in planar
contact with said main surface, to an open position substantially
orthogonal to said main surface and substantially parallel to said
edge surface, wherein when said means for finding a view is in said
closed position, said means for executing and controlling is covered
and protected by said means for finding a view.
25. A method of taking a photograph of an object using a digital
camera including a camera body having a main surface and a lens
surface substantially orthogonal to the main surface, a photographic
lens positioned on the lens surface, a solid state imaging device,
and an optical viewfinder unit rotatably attached to the camera
body, said method comprising the steps of: rotating the optical
viewfinder unit from a closed position wherein said viewfinder unit
is substantially in planar contact with said main surface to an
open position substantially orthogonal to the main surface and in
a plane substantially parallel to the lens surface; aligning the
object within the optical viewfinder unit; and capturing an image
of the object using the photographic lens and solid state imaging
device, wherein said step of rotating said optical viewfinder unit
from a closed position to an open position uncovers a release button
and control feature of the digital camera.
26. The method as claimed in claim 25, wherein the digital camera
further includes a view plate rotatably attached to the main surface,
the view plate having a hole positioned such that a center of the
hole is substantially in line with an orthogonal line extending
from a center of an optical viewfinder window of the optical viewfinder
unit, said method further comprising the step of moving the view
plate to a position substantially orthogonal to the main surface
and substantially parallel to the surface of the optical viewfinder
window prior to the step of aligning the object within the optical
viewfinder unit.
Digital Camera Patent Description
CROSS REFERENCE TO RELATED APPLICATIONS
This document claims priority and contains subject matter related
to Japanese Patent Application No. 11-080918 filed in the Japanese
Patent Office on Mar. 25, 1999, the entire contents of which are
incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a digital camera that stores image
information obtained by an imaging device in a recording medium,
and more particularly to a digital camera which is compact and has
the convenience of portability.
2. Discussion of the Background
A camera using a photographic film (i.e. a silver halide film camera)
has been generally used for photography. Recently, digital cameras
have become increasingly widespread. In the digital cameras, object
images, such as static images (still images) and moving images (movie
images), are photographed by a solid-state imaging device, such
as a charged coupled device (CCD) or the like, and image data of
the object image are obtained and digitally recorded in a recording
medium such as an IC (integrated circuit) card, a printed circuit
(PC) card with semiconductor memory, a video floppy disk, or the
like.
In the above-described digital camera, almost all functions, except
for optical sub-systems, are digitally performed, including basic
photographing functions, add-on accessory functions, etc. Because
image data is digitally recorded in the recording medium instead
of a photographic film, spaces for a film feeding unit and a film
winding mechanism are not necessary in the digital camera. Therefore,
a layout of each functional element of the digital camera can be
more flexibly made, and the size of the digital camera can be more
compact than that of the camera using a photographic film. Moreover,
operability, portability, and appearance of digital camera can be
enhanced by contriving to appropriately design the layout of each
element of the digital camera.
Because a camera is usually equipped as a portable device for photographing
various events, demand for a compact camera has increased. For example,
the "one-time-use camera" or "disposal camera"
using a photographic film has come into widespread use. This type
of camera is made handy, and low in cost by reducing functions of
the camera.
Similarly, with the widespread use of the digital camera, there
is an increasing demand for a handy, portable, and low-cost digital
camera.
In order to reduce the size of the digital camera, main elements
of the digital camera need to be miniaturized including a photographic
optical system, an imaging device, a recording medium, a digital
circuit unit, a power supply battery, etc. Moreover, a viewfinder
for confirming a photographing range, which is likely to occupy
a relatively large space in the digital camera, also needs to be
compact in the digital camera.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide
a novel digital camera which is compact and has the convenience
of portability.
Another object of the present invention is to provide a novel digital
camera which has a simple configuration and is low in cost.
The digital camera of the present invention includes a camera body
having a main surface and a lens surface substantially orthogonal
to the main surface, a photographic lens of a photographic optical
system, the photographic lens positioned on the lense surface, and
an optical viewfinder unit rotatably attached to the main surface
such that the optical viewfinder unit is rotatable to a position
substantially orthogonal to the main surface and in a plane substantially
parallel to the lens surface.
In one embodiment, the optical viewfinder unit includes a planar
structure having a square shaped optical viewfinder window which
serves as a field frame for defining a range of an object image,
the main surface includes first and second opposing edges and the
optical viewfinder unit is rotatably attached to the main surface
at an axis parallel to and in the vicinity of the second edge, and
a length and width of the optical viewfinder window are set according
to a field angle of the photographic lens and a width of the camera
body defined by a distance from the first edge to the second edge
of the main surface.
In another embodiment, the digital camera further includes a view
plate rotatably attached to the main surface at an axis in the vicinity
of the first edge such that the view plate is moveable to a position
substantially orthogonal to the main surface and substantially parallel
to the surface of the optical viewfinder window, the view plate
having a hole positioned such that a center of the hole is substantially
in line with an orthogonal line extending from a center of the optical
viewfinder window.
In yet another embodiment, the optical viewfinder unit includes
a planar structure having a square shaped optical viewfinder window,
at least one transparent member positioned in the optical viewfinder
window, and a pattern of marks printed on the at least one transparent
member and configured to assist a user of the digital camera in
defining a photographing range of an object image. The at least
one transparent member may be a single transparent member having
a predetermined thickness and having the pattern of marks printed
on opposing sides of the transparent member, or alternatively may
be two or more transparent members each having a portion of the
pattern of marks printed thereon. The position of the pattern of
marks is determined according to the thickness of the transparent
member or the distance between transparent members, and a field
angle of a photographing lens of the photographic optical system.
In yet another embodiment of the present invention, the optical
viewfinder unit is rotatable from a closed position wherein the
optical viewfinder unit is in planar contact with the main surface,
to an open position wherein the optical viewfinder unit is in the
position substantially orthogonal to the main surface and in a plane
substantially parallel to the lens surface, and the digital camera
includes a power switch configured to be in an on state when the
optical viewfinder is in the open position, and in an off state
when the optical viewfinder is in the closed position.
In still another embodiment, the digital camera includes an operation
unit having at least one operation button arranged on the main surface,
wherein when the optical viewfinder unit is in the closed position,
the at least one operation button is covered and protected from
unintentional operation.
Finally, another embodiment of the digital camera includes a release
button of an operation unit is arranged on an upper surface of a
camera body. The upper surface of the camera body is substantially
orthogonal to a surface where an object lens of a photographic optical
system is exposed. An optical viewfinder unit is rotatable around
an axis that is provided in the vicinity of the edge of the upper
surface, connecting to the edge of the surface where the object
lens of the photographic optical system is exposed. The optical
viewfinder unit rotates approximately 90-degree angle from the position
in which the optical viewfinder unit is in planar contact with the
upper surface of the camera body. When the optical viewfinder unit
is in planar contact with the upper surface of the camera body,
the optical viewfinder unit covers at least the release button of
the operation unit. The optical viewfinder unit rotates to the position
in which the optical viewfinder unit vertically stands relative
to the upper surface of the camera body so that the optical viewfinder
unit is used for confirming a photographing range of an object image.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the present invention and many
of the attendant advantages thereof will be readily obtained as
the same becomes better understood by reference to the following
detailed description when considered in connection with the accompanying
drawings, wherein:
FIG. 1 is a perspective view illustrating an outward appearance
of a digital camera according to a first embodiment of the present
invention when the digital camera is not in a photographing mode;
FIG. 2 is a perspective view illustrating an outward appearance
of the digital camera according to the first embodiment of the present
invention when the digital camera is in the photographing mode;
FIG. 3 is a perspective view of the digital camera according to
the first embodiment of the present invention in which square frames
are printed on transparent members;
FIG. 4 is a perspective view of the digital camera according to
the first embodiment of the present invention in which L-shaped
marks are printed on the transparent members;
FIG. 5 is a perspective view illustrating an outward appearance
of a digital camera according to a second embodiment of the present
invention when the digital camera is in a photographing mode;
FIG. 6 is a perspective view illustrating an outward appearance
of a digital camera according to a third embodiment of the present
invention when the digital camera is in a photographing mode; and
FIG. 7 is a block diagram illustrating an electrical system configuration
of the digital camera of FIGS. 1 through 6 of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals
designate identical or corresponding parts throughout the several
views, embodiments of the present invention are now described. FIG.
1 is a perspective view illustrating an outward appearance of a
digital camera according to a first embodiment of the present invention
when the digital camera is not in a photographing mode. FIG. 2 is
a perspective view illustrating an outward appearance of the digital
camera according to the first embodiment of the present invention
when the digital camera is in the photographing mode. The digital
camera illustrated in FIGS. 1 and 2 includes a camera body 1, an
optical viewfinder unit 2, a photographic optical system 3, a release
button 4, a photographing mode button 5, a transmission button 6,
a display unit 122, and a chain (or a strap) 7.
The camera body 1 is formed, for example, in the shape of an approximately
rectangular solid and includes a chain attaching part 1a on one
side surface thereof. For the convenience of portability, the camera
body 1 is formed in a compact rectangular solid of about 60 mm (length).times.about
40 mm (width).times.about 15 mm (height).
Provided on an upper surface of the camera body 1 is the optical
viewfinder unit 2. Further, the photographic optical system 3 is
provided to one side surface of the camera body 1 such that an object
lens of the photographic optical system 3 is visible from the outside
of the camera body 1. The optical viewfinder unit 2 is rotatably
hinged on the upper edge of the side surface where the object lens
of the photographic optical system 3 is exposed. Moreover, the optical
viewfinder unit is of simple construction and provides a view of
the actual image to be photographed as opposed to using a Liquid
Crystal Display or other electronic device to generate or display
an image being photographed or captured. This construction allows
the digital camera of the present invention to be compact and light
weight.
Specifically, the optical viewfinder unit 2 is rotatable around
an axis which is provided in the vicinity of and parallel to the
edge of the upper surface of the camera body 1. The optical viewfinder
unit 2 rotates approximately 90-degrees from the position in which
the optical viewfinder unit 2 is in intimate planar contact with
the upper surface of the camera body 1 (hereinafter referred to
as the closed position) to the position in which the optical viewfinder
unit 2 vertically stands (hereinafter referred to as the opened
position). Although it is not shown, a mechanism for locking the
optical viewfinder unit 2 at the opened position is provided in
the camera body 1 to prevent the optical viewfinder unit 2 from
unintentionally rotating from the opened position to the closed
position. Further, a power supply switch (not shown in FIGS. 1 and
2, but indicated by reference numeral 130 in FIG. 7) is provided
in the camera body 1 and is switched on and off in response to the
operation of the optical viewfinder unit 2. Specifically, the power
supply switch 130 is configured to turn on a power supply (not shown)
of the digital camera when the optical viewfinder unit 2 reaches
the opened position and vertically stands to the upper surface of
the camera body 1, and is configured to turn off the power supply
of the digital camera when the optical viewfinder unit 2 reaches
the closed position.
In the optical viewfinder unit 2, a transparent optical viewfinder
window 2a is formed in a square shape and is typically called an
action viewfinder or a sports viewfinder. The transparent optical
viewfinder window 2a includes two or more transparent members, such
as glass or plastic, which are spaced apart from each other a predetermined
distance. A pair of frame lines 20a for defining a photographing
range of an object image is printed on each of the transparent members
such that respective frame lines 20a are parallel to the sides of
the transparent optical viewfinder window 2a. The length of the
frame lines 20a and the distance between the frame lines 20a on
respective transparent members are determined according to the distance
between the transparent members and a field angle of a photographing
lens of the photographic optical system 3. The user looks at an
object image through the transparent optical viewfinder window 2a,
and can confirm the photographing range which is defined by adjusting
a distance between the user's eye and the transparent optical viewfinder
window 2a such that respective frame lines 20a on the front and
back transparent members are overlaid. In order for the user to
more easily confirm the photographing range, a pair of lines connecting
both ends of the frame lines 20a to form square frames 20b may be
printed on the respective transparent members as illustrated in
FIG. 3. The square frames 20b may be printed on the respective transparent
members in a similar manner. Alternatively, the transparent optical
viewfinder window 2a may include only one transparent member having
a predetermined thickness. Each pair of frame lines 20a may be printed
on the front and back surface thereof. The length of the frame lines
20a and the distance between the frame lines 20a on respective transparent
members are determined according to the thickness of the transparent
member and the field angle of the photographing lens of the photographic
optical system 3.
Instead of the pair of frame lines 20a and square frames 20b, various
patterns of marks may be printed on the transparent member. On the
transparent member in FIG. 4, L-shaped marks 20c are printed near
four corners of the transparent optical viewfinder window 2a, respectively,
for defining the photographing range. Similar to the frame lines
20a illustrated in FIG. 2, the positions where the L-shaped marks
20c are printed on respective transparent members are determined
according to the distance between the transparent members and the
field angle of the photographing lens of the photographic optical
system 3. Alternative shapes of the L-shaped marks 20c may be employed,
such as a circle.
Arranged on the upper surface of the camera body 1 are the release
button 4, the photographing mode button 5, the transmission button
6, and the display unit 122. The release button 4 is used for executing
a photographing operation (i.e., an image taking in/recording operation).
The photographing mode button 5 is used for switching the photographing
mode. The transmission button 6 is used for transmitting the data
of a recorded image to an external computer (e.g., a personal computer)
that is connected to the digital camera. The display unit 122 includes,
for example, a liquid crystal display (LCD) device or a light-emitting
device, and displays messages indicating the operational conditions
of the digital camera, such as the photographing mode.
When the optical viewfinder unit 2 is closed (i.e., when the optical
viewfinder unit 2 is in intimate contact with the upper surface
of the camera body 1), the optical viewfinder unit 2 covers and
protects the release button 4, the photographing mode button 5,
and the transmission button 6 arranged on the upper surface of the
camera body 1 from being unintentionally operated.
The chain attaching part 1a of the camera body 1 is used for attaching
thereto the removable chain 7 (e.g., a key holding chain) for holding
the digital camera. The user may hook the chain 7 on his or her
clothing to carry the digital camera.
When the user does not photograph and carries the digital camera,
as illustrated in FIG. 1, if the optical viewfinder unit 2 is closed
to be in intimate contact with the upper surface of the camera body
1, the optical viewfinder unit 2 covers and protects the release
button 4, the photographing mode button 5, and the transmission
button 6. Further, as described above, the power supply switch 130
turns off the power supply of the digital camera. Therefore, erroneous
operations of the digital camera can be avoided. Moreover, because
the digital camera is compact in the closed condition, the user
can carry the digital camera, for example, in a pocket or handbag.
When the user photographs, as illustrated in FIG. 2, the optical
viewfinder unit 2 is opened so as to stand vertically to the camera
body 1. Further, as described above, the power supply switch 130
turns on the power supply of the digital camera when the optical
viewfinder unit 2 is opened. Therefore, the user can confirm a photographing
range of an object image in a clear and appropriate visual condition
in the transparent optical viewfinder window 2a.
Referring to FIG. 5, a digital camera according to a second embodiment
of the present invention is described. FIG. 5 is a perspective view
illustrating an outward appearance of the digital camera according
to the second embodiment of the present invention when the digital
camera is in a photographing mode. The configuration of the digital
camera of the second embodiment is substantially the same as that
of the first embodiment illustrated in FIGS. 1 and 2 except the
optical viewfinder unit 2. The optical viewfinder unit 2 of the
digital camera of the second embodiment includes a square-shaped
optical viewfinder window 2b in which no transparent member is provided.
In other words, the optical viewfinder window 2b serves as a field
frame. The length and width of the optical viewfinder window 2b
are set according to the field angle of the photographic lens of
the photographic optical system 3 and the width of the camera body
1 indicated by reference character a' in FIG. 5. The user looks
at an object image through the optical viewfinder window 2b to confirm
the photographing range of the object image. More specifically,
the user puts, for example, his/her nose at a position A in FIG.
5 such that the middle point between his/her eyes is positioned
substantially in line with an orthogonal line extending from the
center of the optical viewfinder window 2b, and the eyes arc substantially
parallel to the surface of the optical viewfinder window 2b. A view
illustrating an outward appearance of the digital camera of the
second embodiment when the digital camera is not in a photographing
mode is omitted, because the view is substantially the same as FIG.
1.
Referring to FIG. 6, a digital camera according to a third embodiment
of the present invention is described. FIG. 6 is a perspective view
illustrating an outward appearance of the digital camera according
to the third embodiment of the present invention when the digital
camera is in a photographing mode. A view illustrating an outward
appearance of the digital camera of the third embodiment when the
digital camera is not in a photographing mode is also omitted because
the view is substantially the same as FIG. 1. The configuration
of the digital camera of the third embodiment is substantially the
same as that of the second embodiment illustrated in FIG. 5 except
the provision of a view plate 10. The view plate 10 is configured
to stand substantially parallel to the surface of the optical viewfinder
window 2b and has a hole 10a such that the center of the hole 10a
is positioned substantially in line with an orthogonal line extending
from the center of the optical viewfinder window 2b. The diameter
of the hole 10a is in a range of about 4 mm to about 7 mm. The view
plate 10 is hinged to the edge of the upper surface of the camera
body 1 which is opposite and substantially parallel to the other
edge of the upper surface of the camera body 1 to which the optical
viewfinder unit 2 hinged. The view plate 10 is rotatable approximately
90-degrees about an axis in the vicinity of the edge of the upper
surface of the camera body 1 to which the view plate 10 is hinged.
The view plate 10 vertically stands relative to the upper surface
of the camera body 1 by rotating from a closed position (i.e., a
position in which the view plate 10 is in intimate contact with
the upper surface of the camera body 1). A mechanism (not shown)
for locking the view plate 10 when the view plate 10 is in the opened
position is provided in the camera body 1 to keep the view plate
10 vertically standing relative to the upper surface of the camera
body 1. When the user photographs, the user opens and rotates the
optical viewfinder unit 2 and the view plate 10 to vertically stand
relative to the upper surface of the camera body 1, respectively,
and to face each other in parallel. The user confirms a photographing
range of an object image by looking at the object image through
the hole 10a of the view plate 10 and the optical viewfinder window
2b. Like the optical viewfinder window 2b of the second embodiment,
the length and width of the optical viewfinder window 2b are set
according to a field angle of a photographing lens of the photographic
optical system 3 and the width a' of the camera body 1. Although
the number of construction parts of the digital camera of the third
embodiment is more than that of the digital camera of the second
embodiment, it is easier for the user to confirm a photographing
range of an object image using the view plate 10 with the hole 10a.
The electrical system configuration of the digital cameras illustrated
in FIGS. 1 through 6 is now described referring to FIG. 7. The exemplary
digital cameras according to the embodiments of the present invention
photograph not only static images (i.e., still images) in a static
image capture mode, but also moving images in a movie capture mode
in which moving image and sound are recorded for a short time.
The digital camera illustrated in FIG. 7 includes a lens system
101, a shutter mechanism 102, a charge coupled device (CCD) 103,
a correlate dual sampling (CDS) circuit 104, a first analog to digital
(A/D) converter 105, a digital signal processing unit 106, a compression
and decompression unit 107, a first-in first-out (FIFO) memory 108,
a card interface (I/F) 109, a PC card 110, a microphone 111, a first
amplifier and filter (AMP/FILTER) 112, a second analog to digital
(A/D) converter 113, a sound data compression and decompression
unit 114, a digital to analog (D/A) converter 115, a second amplifier
and filter (AMP/FILTER) 116, a central processing unit (CPU) 121,
the display unit 122, an operation unit 123, a transmission unit
124, a lens driver 125, a signal generator (SG) 126, a battery 128,
a DC-DC converter 129, and a power supply switch 130.
The photographic optical system 3 for image focusing includes the
lens system 101 and the shutter mechanism 102. The shutter mechanism
102 includes an aperture mechanism and a filter mechanism, and controls
an exposure time when a shutter is released. The shutter mechanism
102 may include an auto focus (AF) mechanism. As the imaging device,
the CCD 103 is used in this embodiment. The CCD 103 converts optical
images, which are imaged through the photographic optical system
3, into electrical signals.
The photograph process system of the digital camera for processing
the optical image signals includes the CDS circuit 104, the first
A/D converter 105, the digital signal processing unit 106, the compression
and decompression unit 107, the FIFO memory 108, and the CPU 121.
The CDS circuit 104 reduces noise in the electrical signals output
from the CCD 103. The first A/D converter 105 converts the analog
image signals, which are input thereto from the CCD 103 through
the CDS circuit 104, into digital image data. In further detail,
the A/D converter 105 converts the signals output from the CCD 103
to digital signals through the CDS circuit 104 with an optimum sampling
frequency.
The digital signal processing unit 106 separates the digital image
data, which is input thereto from the A/D converter 105, into a
color-difference component and a luminance component, and then performs
various processes on each component, including a correcting process
and a pre-process for compression/decompression. The compression/decompression
unit 107 compresses the image data with, e.g., an orthogonal transformation
and a Huffman encoding, and decompresses the image data with, e.g.,
a corresponding Huffman decoding and an inverse orthogonal transformation
in conformity with the Joint Photographic Expert Group (JPEG) standard.
Sound is converted to electrical signals by the microphone 111.
In the first AMP/FILTER 112, the sound signals in a predetermined
band are passed through the first AMP/FILTER 112 and are selectively
amplified. The second A/D converter 113 then converts the sound
signals which have passed through the first AMP/FILTER 112 to digital
sound data with a sampling frequency which is more than double the
frequency of the predetermined band. Then, the sound data compression
and decompression unit 114 compresses and encodes the digital sound
data.
The FIFO memory 108 is a temporary memory device, such as a dynamic
random access memory (DRAM), static RAM, a flash memory, or the
like. The FIFO memory 108 temporarily stores compressed image data
and sound data therein. The compressed image data and sound data
are read out by the card interface 109, and are recorded in the
PC card 110 serving as a record medium connected to the card interface
109. The PC card 110 contains a semiconductor memory or a recognized
equivalent for recording information.
The CPU 121 controls operations of each unit of the digital camera
according to instructions from the operation unit 123. As mentioned
above, the display unit 122 includes, for example, a liquid crystal
display (LCD) device or a light-emitting device, and displays messages
indicating the operational conditions of the digital camera, such
as the photographing mode.
When transmitting data to an external device such as, for example,
a personal computer, the data recorded in the PC card 110 is read
out through the card interface 109 and the FIFO memory 108, decompressed
by the compression/decompression unit 107, and then provided to
the external device through the digital signal processing unit 106.
The sound data is decompressed by the sound data compression and
decompression unit 114 through the FIFO memory 108, converted to
analog signals by the digital to analog (D/A) converter 115, and
is output through the second amplifier and filter (AMP/FILTER) 116.
The operation unit 123 includes various operation devices, such
as the release button 4 for inputting a photographing instruction,
the photographing mode button 5, and the transmission button 6 which
are illustrated in FIG. 2. The transmission unit 124 is controlled
by the CPU 121 to transmit the image data output from the digital
signal processing unit 106 and the sound data output from the second
amplifier and filter (AMP/FILTER) 116 to an external device (e.g.,
a computer), when the transmission button 6 of the operation unit
123 is operated.
The lens driver 125 drives the photographing lens system 101 and
the shutter mechanism 102 according to a control signal provided
by the CPU 121. The signal generator 126 generates drive control
signals such as clock signals, and provides the drive control signals
to the CCD 103, CDS circuit 104, and A/D converter 105 to drive
each unit.
A power supply unit of the digital camera includes the battery
128 and the DC-DC converter 129. As the battery 128, a nickel cadmium
battery, a nickel hydrogen battery, or a lithium battery is used.
The voltage is converted to an appropriate level by the DC-DC converter
129 to be supplied to each unit of the digital camera.
As described above, the power supply switch 130 switches the power
supply in response to the open/close operations of the optical viewfinder
unit 2 relative to the camera body 1. Specifically, the power supply
switch 130 turns on the power supply of the digital camera when
the optical viewfinder unit 2 is opened to vertically stand relative
to the camera body 1, and turns off the power supply of the digital
camera when the optical viewfinder unit 2 is closed to be in intimate
contact with the upper surface of the camera body 1. The power supply
switch 130 sends control signals to the CPU 121 to perform the on-off
control of the power supply to each unit of the digital camera from
the DC-DC converter 129.
When the power supply switch 130 is turned on, the CPU 121 controls
the photograph process system to be in a ready condition so that
the digital camera is in the standby condition for photographing.
In the photographing mode, the user confirms a photographing range
of an object image by looking at the object image through the transparent
optical viewfinder window 2a or the optical viewfinder window 2b
of the optical viewfinder unit 2 in a clear and appropriate visual
condition. After confirming the photographing range of the object
image, the user depresses the release button 4 of the operation
unit 123, and thereby the object image is photographed in the desired
photographing range.
In more detail, when the release button 4 of the operation unit
123 is depressed, the shutter mechanism 102 of the photographic
optical system 3 is opened. Then, the object image is photographed
with the CCD 3 through the lens system 101. The image data of the
object image is written in the PC card 110 through the digital signal
processing unit 106.
When the digital camera is in the standby condition for photographing,
the user can select and set the photographing mode by operating
the photographing mode button 5 and confirming the set of the photographing
mode on the display unit 122. Further, the user can transmit the
photographed image data stored in the PC card 110 to an external
computer through the transmission unit 124.
When the user carries the digital camera, as illustrated in FIG.
1, the optical viewfinder unit 2 is closed to contact the camera
body 1, so that the release button 4, the photographing mode button
5, and the transmission button 6 on the upper surface of the camera
body 1 are covered by the optical viewfinder unit 2, and the power
supply switch 130 is turned off. When the optical viewfinder unit
2 is closed, the digital camera including the camera body 1 and
the optical viewfinder unit 2 is in a shape of a rectangular solid
without projections on the outer surface of the digital camera.
In this closed condition of the optical viewfinder unit 2, because
not only the release button 4, the photographing mode button 5,
and the transmission button 6 of the operation unit 123 are not
exposed but also the power supply switch 130 is turned off, an erroneous
operation of the photograph process system can be prevented. Accordingly,
the user can carry the digital camera without worrying about unintentional
operations of the digital camera.
Because the above-described digital cameras according to the first
through third embodiments include the optical viewfinder unit 2
of simple configuration for confirming a photographing range of
an object image, the number of construction parts of the digital
camera of the present invention is fewer than that of a digital
camera including a liquid crystal display (LCD) for displaying photographed
images. Therefore, a low-cost digital camera is obtained.
Further, because each optical viewfinder unit 2 according to the
first through third embodiments also serves as the cover for the
camera body 1, the space for the optical viewfinder unit 2 is saved
in the digital camera. Accordingly, the digital camera can be made
compact and portable.
In the above-described digital camera, although it is configured
such that the power supply of the digital camera is turned on or
off in response to the opening or closing operation of the optical
viewfinder unit 2 relative to the camera body 1, the power supply
may be turned on or off by manipulating a dedicated switch if the
release button 4, the photographing mode button 5, and the transmission
button 6 on the upper surface of the camera body 1 of the operation
unit 123 are covered by the optical viewfinder unit 2.
Moreover, in the above-described digital camera, the locking mechanism
is provided to prevent the optical viewfinder unit 2 from being
closed when the optical viewfinder unit 2 vertically stands to the
camera body 1. However, an alternative locking mechanism can be
provided, in which a spring or other similar element is biased when
the optical viewfinder unit 2 is rotated from the opened position
to the closed position and the optical viewfinder unit 2 is locked
in the closed condition. In this locking mechanism, the optical
viewfinder unit 2 pops open when the optical viewfinder unit 2 is
unlocked, and thus the digital camera quickly becomes ready for
photographing mode. The above alternative locking mechanism is also
applicable to the view plate 10 of the third embodiment.
Numerous additional modifications and variations of the present
invention are possible in light of the above teachings. It is therefore
to be understood that within the scope of the appended claims, the
present invention may be practiced otherwise than as specifically
described herein.
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