Digital Camera Patent Abstract
An array of photosensors, used for imaging in a digital camera,
is used to detect pressure, for example pressing by a finger, on
an attached lens cap. The location of the pressure may be used to
directly position a cursor, or the location of the pressure may
be used to control direction of movement of a cursor. The lens cap
is designed so that pressure on an outer layer changes reflectance
or color of an area on an inner layer. For example, an inner layer
may be translucent and dark and separated by a gap from a light
colored outer layer. When the outer layer is pressed against the
inner layer, the area of contact has an increased reflectance. Alternatively,
the inner layer may be transparent, and a colored liquid may separate
the inner layer from a light colored outer layer. When the outer
layer is pressed against the inner layer, the area where all the
liquid is displaced has the color of the outer layer. Digital Camera Patent Claims
What is claimed is:
1. A digital camera comprising: an array of photosensors; a lens;
and a cap adapted to cover the lens, the cap having an interior
side and an exterior side, the interior side being viewable by the
array of photosensors when the cap is covering the lens, the interior
side having a first reflectance when no pressure is placed onto
the exterior side, wherein pressure on the exterior side causes
an area of the interior side to change to a second reflectance,
the second reflectance not equal to the first reflectance.
2. The camera of claim 1, further comprising: a display, the display
adapted to present a cursor; and the area having the second reflectance
being used to control a position of the cursor on the display.
3. The camera of claim 1, further comprising: a display, the display
adapted to present a cursor; and the area having the second reflectance
being used to control a direction of motion of the cursor on the
display.
4. A digital camera comprising: an array of photosensors; a lens;
and a cap adapted to cover the lens, the cap having an interior
side and an exterior side, the interior side being viewable by the
array of photosensors when the cap is covering the lens, the interior
side having a first color when no pressure is placed onto the exterior
side, wherein pressure on the exterior side causes an area of the
interior side to change to a second color, the second color not
equal to the first color.
5. The camera of claim 4, further comprising: a display, the display
adapted to present a cursor; and the area having the second color
being used to control a position of the cursor on the display.
6. The camera of claim 4, further comprising:. a display, the display
adapted to present a cursor; and the area having the second color
being used to control a direction of motion of the cursor on the
display.
7. A method of controlling position of a cursor on a display on
a camera, the method comprising the following steps: pressing onto
an exterior surface of a lens cap, thereby causing an area in the
interior of the lens cap to change reflectance; imaging, by an array
of photosensors, the interior of the lens cap; and moving the cursor
to a position on the display that corresponds to the position, within
the image of the interior of the lens cap, of the area having a
changed reflectance.
8. A method of controlling position of a cursor on a display on
a camera, the method comprising the following steps: pressing onto
an exterior surface of a lens cap, thereby causing an area in the
interior of the lens cap to change color; imaging, by an array of
photosensors, the interior of the lens cap; and moving the cursor
to a position on the display that corresponds to the position, within
the image of the interior of the lens cap, of the area having a
changed color.
9. A method of controlling motion of a cursor on a display on a
camera, the method comprising the following steps: pressing onto
an exterior surface of a lens cap, thereby causing an area in the
interior of the lens cap to change reflectance; imaging, by an array
of photosensors, the interior of the lens cap; and moving the cursor
on the display in a direction that corresponds to a direction defined
by a position, within the image of the interior of the lens cap,
of the area having a changed reflectance, relative to a reference
position.
10. A method of controlling motion of a cursor on a display on
a camera, the method comprising the following steps: pressing onto
an exterior surface of a lens cap, thereby causing an area in the
interior of the lens cap to change color; imaging, by an array of
photosensors, the interior of the lens cap; and moving the cursor
on the display in a direction that corresponds to a direction defined
by a position, within the image of the interior of the lens cap,
of the area having a changed color, relative to a reference position.
Digital Camera Patent Description
FIELD OF INVENTION
This invention relates generally digital cameras to and more specifically
to a device used to control a cursor position on a display on a
digital camera.
BACKGROUND OF THE INVENTION
Digital still cameras and digital video cameras often include a
multipurpose display on the back of the camera. The display may
be used to show one or more images, or the display may be used for
various control functions. For example, multiple reduced size ("thumbnail")
images may be arranged on the display so that a camera operator
may select an image for viewing, or for transmission to a storage
device or computer. Alternatively, a camera may include various
image editing functions, so that areas of an image need to be selected
for editing. Alternatively, the display may present a menu of camera
control functions, and the camera operator may need to scroll through
and select various control choices. Typically, selection of one
image from an array of images, or defining an area for editing,
or selection of one choice from a menu of items, requires movement
of a cursor over the image or menu item to be selected, followed
by pressing a key or button to initiate the selection. In general,
just as cursors are controlled for computer displays, a cursor in
a digital camera may be controlled, for example, by a mouse, up/down
control buttons, levers ("joystick"), a track-ball, rocking
platform switches, or touch sensitive pads that track finger movement.
However, each of these cursor control devices require extra parts,
and require space on the surface of the camera or appendages to
the camera. In addition, some devices requiring discrete movements,
such as rocker switches, may be less intuitive to an operator compared
to devices that use continuous movement, such as a mouse, which
people are accustomed to using with computer displays. Small cameras
may have very limited space for controls. There is a need for simple
low-cost cursor control, with continuous control similar to use
of a mouse, without requiring devices that consume space on the
surface of the camera.
SUMMARY OF THE INVENTION
The array of photosensors used for imaging is used to detect pressure,
for example pressing by a finger, on an attached lens cap. The location
of the pressure may be used to directly position a cursor, or the
location of the pressure may be used to control direction of movement
of a cursor. As a result, using the lens cap for cursor control
closely mimics touch pad pointing devices, providing continuous
position or motion control. The lens cap, for example, may comprise
two layers that are separated. The inside layer may be a rigid,
translucent, dark colored material. The outer layer may be flexible
and light colored. When the outer layer is pressed against the inner
layer, the reflectance on the inner surface at the point of contact
with the light material becomes much higher than the reflectance
where there is no contact with the light colored material. Alternatively,
the lens may enclose a liquid so that the color normally seen by
the array of photosensors is the color of the liquid. Then, when
the outer layer of the lens cap is depressed, a small area of the
outer layer displaces the liquid and touches the inner layer, so
that the a color of the small area seen by the array of photosensors
is the color of the outer layer of the lens cap. Alternatively,
thermally sensitive materials may be used, so that the lens cap
changes color in an area pressed by a relatively warm finger.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a camera in accordance with the
invention.
FIG. 2 is a cutaway side view of the camera of FIG. 1.
FIG. 3 is a view of the inside of the lens cap illustrated in FIGS.
1 and 2.
FIG. 4 is an expanded cutaway side view of the lens cap illustrating
one example embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
FIG. 1 illustrates an example of a digital still camera in accordance
with the invention. The invention is equally applicable to digital
video cameras. In FIG. 1, a camera 100 has a display 102 on the
back. In addition, the camera has a lens 104, covered by a removable
lens cap 106. In FIG. 1, the display 102 is presenting an image
108 that has been captured earlier. The display 102 also is presenting
a control menu 110, with a list of choices, for example, to delete
or store the image, or to crop or otherwise resize the image, or
to provide other editing functions. Also illustrated on display
102 is an image of a moveable cursor 112 used to select items being
presented, in this example one of the control menu items.
As illustrated in FIG. 2, the camera 100 also has a array of photosensors
114, used to capture images. Images are focused by the lens 104
onto the array of photosensors 114 and electronic charges from the
photosensors are shifted into analog-to-digital converters (not
illustrated), and resulting digital values are stored in a memory
(not illustrated). The camera also includes a processor (not illustrated)
that controls imaging and storage, and controls the display 102.
In FIG. 2, the lens cap 106 is attached (it is removed for image
capture) and a finger 116 is pressing on the lens cap 106 to control
the cursor 112 (FIG. 1) on the display 102. Also illustrated in
FIG. 2 is a light 120, used to illuminate the back of the lens cap
106, so that if the lens cap 106 is opaque, the light 120 enables
the array of photosensors 114 to image the back of the lens cap.
FIG. 3 illustrates the back 122 of the lens cap 106, as viewed
by the array of photosensors 114 (FIG. 2). In FIG. 3, most of the
back of the lens cap 106 is, for example, a light color. Where pressure
is applied to the front of the lens cap, an area 124 is a dark color.
The choice of light and dark is arbitrary and for illustration only.
The only important parameter is that the processor in the camera
must be able to distinguish, in an image of the back 122, digital
intensity or color values in an image representing the area 124
from digital intensity or color values representing the rest of
the back 122.
FIG. 4 illustrates one example of a lens cap that provides a color
change in an area that is pressed. In FIG. 4, the lens cap has an
inner layer 122, a gap 126, and an outer layer 128. For example,
the inner layer 122 may be rigid, translucent, and dark colored.
The outer layer 128 may be flexible and light colored. When the
outer layer is pressed against the inner layer, the reflectance
of the inner layer is increased in the area of contact. As an alternative,
the gap 126 may be filled with a liquid and the liquid may be colored,
for example, blue. The inner layer may be transparent and the outer
layer may again be white. If the outer layer is not pressed, then
the photosensor array images only blue. If the outer layer 128 is
deflected so that the outer layer 128 touches the transparent inner
layer 122, then the photosensor array images the color of the outer
layer (white in the example) in the area where the liquid 126 is
completely displaced. A suitable example material for the outer
layer 128 is polyvinyl chloride, which is flexible and available
in many colors.
As an alternative to the multilayer configuration of FIG. 4, the
lens cap may be fabricated from a material that changes color when
heated. Pressing a finger onto the material then causes a local
color change. If the material is sufficiently thin, the color change
will be visible on both sides of the lens.
When the lens cap is covering the lens and the camera is being
controlled, the array of photosensors images the back of the lens
cap, and the resulting digital image pixels may be associated with
individual pixels in the display 102. The processor may place the
cursor 124 at an X,Y location in the display defined by a geometric
attribute of the area 124. For example, the X extent and Y extent
of area 124 may be determined and a center point may be defined
as the center of the X and Y extents. Alternatively, the center
point of the area 124 (or any other point consistently defined by
the area 124) may define a direction of movement of the cursor.
That is, the center point of area 124 relative to a reference point
(for example, a point corresponding to the center point of display
102) defines a direction, and the processor may move the cursor
slowly in that relative direction. Motion is stopped by simply removing
the pressure. A button or switch (not illustrated) on the camera
may be used as the functional equivalent of a mouse button to initiate
selection.
Note that it is not necessary to focus onto the interior surface
of the lens cap. That is, a defocused spot is still adequate for
cursor control. Note also that there are many variations of lens
caps, so that the lens cap may be, for example, a sliding door,
or flip-up door over a retracted lens.
In summary, the invention provides cursor control with continuous
control. The lens cap is a separate replaceable unit that does not
require any electrical or mechanical coupling to the camera. The
only additional part required, other than the lens cap, is a light
for interior illumination. Depending on the display technology,
or the display technology used in a viewfinder, a light may already
be present for back lighting a display, and the light may also be
used to illuminate the back of the lens cap.
The foregoing description of the present invention has been presented
for purposes of illustration and description. It is not intended
to be exhaustive or to limit the invention to the precise form disclosed,
and other modifications and variations may be possible in light
of the above teachings. The embodiment was chosen and described
in order to best explain the principles of the invention and its
practical application to thereby enable others skilled in the art
to best utilize the invention in various embodiments and various
modifications as are suited to the particular use contemplated.
It is intended that the appended claims be construed to include
other alternative embodiments of the invention except insofar as
limited by the prior art. |