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Digital Camera Patent Abstract
A method according to one embodiment may include generating a signal
indicative of ambient light in the vicinity of an LCD panel comprised
in a digital camera. The method may also include controlling at
least one of a brightness and contrast of the LCD panel based at
least in part on the signal indicative of ambient light in the vicinity
of an LCD panel. Of course; many alternatives, variations, and modifications
are possible without departing from this embodiment.
Digital Camera Patent Claims
What is claimed is:
1. A brightness/contrast control system for an LCD panel display
comprised in a digital camera, comprising: an LCD panel; an optical
sensor generating a signal indicative of ambient light in the vicinity
of said LCD panel; and a controller capable of generating at least
one of a power and contrast control signal to control at least one
of the brightness and contrast of said LCD panel based at least
in part on said signal indicative of ambient light in the vicinity
of said LCD panel.
2. The system of claim 1, wherein: said controller further capable
of receiving a preset value signal indicative of at least one of
a preset brightness and preset contrast of said LCD panel.
3. The system of claim 1, wherein: said controller capable of controlling
at least one of said brightness and said contrast based on a linear
relationship between said ambient light and at least one of said
LCD panel brightness and said LCD panel contrast.
4. The system of claim 1, wherein: said digital camera is selected
from a digital still camera and a digital video camera.
5. The system of claim 1, further comprising: an image sensor capable
of sensing the light characteristics of an image, said image sensor
further capable of generating a signal indicative of the light characteristics
of the sensed image, said controller further capable controlling
at least one of the brightness and contrast of said LCD panel based
at least in part on said signal indicative of the light characteristics
of the sensed image.
6. The system of claim 1, wherein: said controller is further capable
of generating at least one of a power and contrast control signal
to power off said LCD panel if said light in the vicinity of said
LCD panel equals or exceeds at least one of a maximum viewable brightness
and contrast level.
7. An apparatus, comprising, a controller capable of controlling
at least one of brightness and contrast of an LCD panel display
comprised in a digital camera based at least in part on ambient
light conditions in the vicinity of said LCD panel.
8. The apparatus of claim 7, wherein: said controller further capable
of receiving a preset value signal indicative of at least one of
a preset brightness and preset contrast of said LCD panel.
9. The apparatus of claim 7, wherein: said controller capable of
controlling at least one of said brightness and said contrast based
on a linear relationship between said ambient light and at least
one of said LCD panel brightness and said LCD panel contrast.
10. The apparatus of claim 7, wherein: said digital camera is selected
from a digital still camera and a digital video camera.
11. The apparatus of claim 7, further comprising: said controller
further capable controlling at least one of the brightness and contrast
of said LCD panel based at least in part on light characteristics
of an image sensed by said digital camera.
12. The apparatus of claim 7, wherein: said controller is further
capable of controlling said LCD panel to power off said LCD panel
if said light in the vicinity of said LCD panel equals or exceeds
at least one of a maximum viewable brightness and contrast level.
13. A method, comprising: generating a signal indicative of ambient
light in the vicinity of an LCD panel comprised in a digital camera;
and controlling at least one of a brightness and contrast of said
LCD panel based at least in part on said signal indicative of ambient
light in the vicinity of an LCD panel.
14. The method of claim 13, wherein: said controller further capable
of controlling at least one of a brightness and contrast of said
LCD panel based at least in part on a preset value signal indicative
of at least one of a preset brightness and preset contrast of said
LCD panel.
15. The method of claim 14, wherein: said controller further capable
of controlling at least one of a brightness and contrast of said
LCD panel based at least in part on a on light characteristics of
an image sensed by said digital camera.
16. The method of claim 13, further comprising: controlling said
LCD panel to power off said LCD panel if said light in the vicinity
of said LCD panel equals or exceeds at least one of a maximum viewable
brightness and contrast level.
Digital Camera Patent Description
FIELD
[0001] The present disclosure relates to a digital camera capable
of brightness and contrast control.
BACKGROUND
[0002] The handheld consumer devices are mainly powered by the
battery. The power consumption of the system will affect the battery
life. In the DSC case, the power consumption will limit how many
pictures can be taken by that camera; this is one of the key parameters
for the digital camera design. There are many power management techniques
used to reduce the total power consumption of the digital camera.
For example, improve the efficiency of the DC/DC converter or shut
down power for the circuits which is not needed. The LCD panel on
the digital camera is almost always turned on when the digital camera
is ON. For example, it is used as the view finder when the user
needs to take picture. It is also required when the user reviews
pictures taken with the digital camera. At the same time the LCD
panel is consuming about 15% of the total power consumption. A conventional
digital camera does not include a mechanism to reduce power consumption
by adjusting power to the LCD panel based on ambient light conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] Features and advantages of embodiments of the claimed subject
matter will become apparent as the following Detailed Description
proceeds, and upon reference to the Drawings, wherein like numerals
depict like parts, and in which:
[0004] FIG. 1 is a diagram illustrating a system embodiment;
[0005] FIG. 2 is a diagram illustrating another system embodiment;
and
[0006] FIG. 3 is a diagram illustrating exemplary operational characteristics
according to one embodiment.
[0007] Although the following Detailed Description will proceed
with reference being made to illustrative embodiments, many alternatives,
modifications, and variations thereof will be apparent to those
skilled in the art. Accordingly, it is intended that the claimed
subject matter be viewed broadly, and be defined only as set forth
in the accompanying claims.
DETAILED DESCRIPTION
[0008] FIG. 1 illustrates a system embodiment 100 of the claimed
subject matter. The system 100 may generally include a digital camera
114. The digital camera 114 may comprise a still image camera or
a digital video camera. The digital camera 114, as provided in this
embodiment, may include a power button 102, an operating mode selection
button 104, a user interface control button 106, an optical viewfinder
108 and an LCD panel 110. In this embodiment, a light sensor 112
may be included. The light sensor may be positioned at any location
on the digital camera, and in this embodiment, the light sensor
112 may be positioned in proximity to the LCD panel 110. The light
sensor may be capable of generating a signal indicative of ambient
light conditions. Such a signal may be used by circuitry comprised
in the digital camera to adjust the brightness of the LCD panel
110, as will be described in greater detail herein.
[0009] It should be understood at the outset that certain components
of the digital camera 114 set forth above may comprise conventional,
custom, and/or proprietary components. For example, power button
102 may represent a conventional switch which may be provided on
a digital camera. Likewise, operating mode selection button 104
and/or user interface control button 106 and/or optical viewfinder
108 and/or LCD panel 110 may represent conventional configurations.
Alternatively, in other embodiments any or all of these components
may be substituted for currently available and/or after-developed
equivalent structures, and/or equivalent functional objects (such
as may be implemented in firmware) without departing from the present
disclosure. Further, it is to be understood that the present disclosure
is of broad scope and it is fully contemplated herein that such
equivalents may be used in any embodiment described herein.
[0010] FIG. 2 depicts another system embodiment 200 of the claimed
subject matter. This embodiment may comprise digital camera that
comprises controller circuitry 202 (hereinafter "controller")
that may be capable of performing all or part of operating task
associated with the digital camera. As used herein, "circuitry"
may comprise, for example, singly or in any combination, hardwired
circuitry, programmable circuitry, state machine circuitry, and/or
firmware that stores instructions executed by programmable circuitry.
Controller 202 may comprise, for example, an application specific
integrated circuit (ASIC), a microprocessor integrated circuit and/or
a digital signal processing unit integrated circuit. As used in
any embodiment herein, an "integrated circuit" means a
semiconductor device and/or microelectronic device, such as, for
example, a semiconductor integrated circuit chip. Of course, digital
camera 114 may also comprise memory (not shown) which may comprise
one or more of the following types of memory: semiconductor firmware
memory, programmable memory, non-volatile memory, read only memory,
electrically programmable memory, random access memory, flash memory,
magnetic disk memory, and/or optical disk memory. Either additionally
or alternatively, memory may comprise other and/or later-developed
types of computer-readable memory. Machine-readable firmware program
instructions may be stored in memory. As described below, these
instructions may be accessed and executed by controller 202, and
these instructions may result in controller 202 performing the operations
described herein as being performed by controller 202.
[0011] In this embodiment, controller 202 may be capable of generating
one or more signals to adjust the brightness of the LCD panel 110,
in a manner described herein. Ambient light sensor 112 may be capable
of generating signal 203 indicative and/or proportional to ambient
light conditions. Such ambient light conditions may be ambient light
conditions in the vicinity of the LCD panel (such as alluded to
above with reference to FIG. 1), or may be general ambient light
conditions of the operating environment of a digital camera 114.
Controller 202 may be capable of receiving signal 203 and generating
a control signal 205. Control signal 205 may be capable of adjusting
the brightness of the LCD panel 110. "Vicinity" as used
in any embodiment herein shall be construed broadly to mean any
special relationships between components described herein as being
in the "vicinity" of one another. Thus, for example, light
sensor 112 may be placed anywhere on the digital camera (for example,
anywhere on the housing of the digital camera as depicted in FIG.
1) and is deemed to be in the vicinity of the LCD panel 110.
[0012] LCD panel 110 may comprise, for example, a white light emitting
diode (WLED) that may be capable of lighting the LCD panel 110.
Alternatively, the LCD panel may comprise a fluorescent lighting
system and/or other light source to light the panel. In this embodiment,
control signal 205 may be capable of controlling the amount of light
produced by the LCD panel. Control signal 205 may be capable of
adjusting the amount of power delivered to the light. For example,
control signal 205 may supply a controllable current to WLED that
lights the LCD panel. Alternatively, camera 114 may comprise DC/DC
converter circuitry capable of generating a DC signal to the light,
and control signal may comprise a pulse width modulated (PWM) signal
capable of controlling the output of a DC/DC converter circuitry
(for example, by controlling the pulse width of the PWM signal).
[0013] Light sensor 112 may comprise a photo-diode, photo-transistor
(bipolar or MOS type), photo-cell, and/or a photo-resistance type
of light sensor capable of generating a signal 203 indicative of
or proportional to ambient light conditions.
[0014] In this embodiment, controller 202 may receive signal 203
and generate control signal 205 to adjust the brightness of the
lamp based on ambient light conditions. Additionally or alternatively,
controller 202 may be capable of generating signal 205 to adjust
the contrast of the LCD panel 110 based on ambient light conditions.
Thus, for example, if ambient light in the vicinity of the LCD panel
114 increases, controller 202 may generate control signal 205 to
increase the brightness of the panel 114. Conversely, if ambient
light in the vicinity of the LCD panel 114 decreases, controller
202 may generate control signal 205 to decrease the brightness of
the panel 114. Thus, signal 203 may be used by controller 202 as
a feedback signal.
[0015] The controller 202 may also be capable of receiving a preset
value signal 207. Signal 207 may represent a preset LCD panel brightness
value, as may be provided by a user of the camera 114. In this embodiment,
controller 202 may be capable of receiving signal 203 as another
feedback input. Signal 203 may operate as a command signal that
sets a threshold level for the controller 202. Thus, for example,
the preset value signal 207 may be used by the controller 202 to
set a desired brightness value which, in turn, may cause controller
202 to override signal 203, or provide a threshold to limit a range
of brightness variations, thus permitting a user to operate the
panel display at a desired brightness level. Alternatively, and
without departing from this embodiment, signal 207 may operate as
a "ceiling" or "floor" value. In this instance,
controller 202 may be capable of comparing signal 207 with signal
203 to ensure that the panel brightness does not exceed or fall
below the brightness level indicated by signal 207, in addition
to the comparison of signals 207 and 203 described above.
[0016] Preset value signal 207 may be generated by, for example,
a variable resistor (e.g., user controlled potentiometer) located
on the external housing of camera 114. Alternatively, user input
circuitry may comprise a specified computer operation, which may
include a selected button operations and/or menu selections. Such
an implementation may include, for example, software and/or firmware
instructions, executed by the camera. Alternatively, preset value
signal 207 may be generated by preprogrammed and/or user programmable
circuitry that is capable of generating a preprogrammed (or user
programmable) preset value signal 207.
[0017] FIG. 3 depicts a graph 300 of exemplary operating characteristics
according to one embodiment. In FIG. 3, the system 100 and 200 depicted
in FIG. 1 and FIG. 2 have been omitted for clarity, but it is to
be understood that the exemplary operating characteristics described
with reference to FIG. 3 may be implemented in a manner consistent
with an embodiment depicted in FIG. 1 and/or FIG. 2, or alternatively
in other system implementations, without departing from this embodiment.
[0018] The x-axis 302 represents ambient light intensity and the
y-axis 304 represents brightness and/or contrast of the LCD panel
114. In this embodiment, ambient sensor 112 may have a maximum detectible
light intensity level, as may be represented by the substantially
vertical line 306. Also, the LCD panel 114 may have a maximum viewable
brightness and/or contrast level, as may be represented by an asymptote
308, and a minimum viewable brightness and/or contrast level, as
may be represented by an asymptote 310. In operation, controller
202 may adjust the brightness/contrast of the LCD panel 114 based
on the ambient light detected from sensor 112. This operation is
depicted as a linear relationship 312 between levels 310 and 308.
Of course, controller 202 may be capable of generating other relationships
between ambient light levels and LCD panel brightness/contrast,
for example, logarithmic, quadratic, and/or other non-linear relationships.
[0019] In this embodiment, if the ambient light level is equal
to, or exceeds a maximum viewable brightness and/or contrast level
308, controller 202 may be capable of generating a control signal
205 to power down the LCD panel. Thus, battery power may be saved
by powering off the LCD panel 110 under circumstances where the
user could not view the LCD panel.
[0020] In alternative embodiments, and referring again to the system
embodiment of FIG. 2, the digital camera 114 may also comprise an
image sensor 210 (for example, a charge-coupled device (CCD) or
CMOS device), capable of sensing the light characteristics of an
image that may be captured by a lens (not shown) comprised in a
digital camera. The image sensor 210 may be capable of generating
a signal 211 indicative of an image captured by the lens. Controller
202 may be capable of displaying an image captured by the mage sensor
210 on the LCD display 110. Signal 211 may be indicative of the
light characteristics of the light incident upon the camera lens.
Controller 202 may be capable of receiving the signal indicative
of the light characteristics of the light incident upon the lens,
and may be further capable of using this signal as additional feedback
information to control the brightness and/or contrast of the LCD
panel. For example, if signal 211 indicates a bright image, controller
202 may be capable of adjusting the brightness and/or contrast of
the LCD based at least in part on the value of signal 211.
[0021] Thus, in summary, at least one embodiment herein provides
a brightness/contrast control system for an LCD panel display comprised
in a digital camera. The system may include an LCD panel and an
optical sensor generating a signal indicative of ambient light around
the LCD panel. The system may also include a controller capable
of generating at least one of a power and contrast control signal
to control at least one of the brightness and contrast of the LCD
panel based at least in part on the signal indicative of ambient
light around the LCD panel. Advantageously, a digital camera according
to at least one embodiment herein may be capable of using ambient
light information to close the loop on the feedback information
supplied to a controller. Additionally, a digital camera according
to at least one embodiment herein may be capable of automatically
adjusting the LCD panel brightness and/or contrast based on ambient
light conditions. Advantageously, these features may permit the
digital camera of these embodiments to exhibit enhanced versatility
and utility compared to the prior art, and may reduce design costs
and power requirements by employing the brightness and/or contrast
control system described herein compared to the prior art. Further,
although specific utility for the present disclosure has been described
with reference to a digital camera, it is equally contemplated herein
that the present disclosure may find utility in any hand-held or
portable electronic device where brightness and/or contrast control
of an LCD display may be desired.
[0022] The terms and expressions which have been employed herein
are used as terms of description and not of limitation, and there
is no intention, in the use of such terms and expressions, of excluding
any equivalents of the features shown and described (or portions
thereof), and it is recognized that various modifications are possible
within the scope of the claims. Other modifications, variations,
and alternatives are also possible. Accordingly, the claims are
intended to cover all such equivalents.
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