U.S. patent application number 10/722084 was filed with the patent office on 2004-06-03 for brightness controlling apparatus, brightness adjusting system, computer system, liquid crystal display unit, brightness controlling method, computer software, and storage medium.
This patent application is currently assigned to International Business Machines Corporation. Invention is credited to Kawano, Seiichi.
Application Number | 20040104919 10/722084 |
Document ID | / |
Family ID | 18745132 |
Filed Date | 2004-06-03 |
United States Patent
Application |
20040104919 |
Kind Code |
A1 |
Kawano, Seiichi |
June 3, 2004 |
Brightness controlling apparatus, brightness adjusting system,
computer system, liquid crystal display unit, brightness
controlling method, computer software, and storage medium
Abstract
An apparatus and method for enabling screen brightness of a
display unit to be adjusted automatically according to display
brightness, thereby improving the visibility of the display screen
to a viewing user. A brightness adjusting system including a gray
scale gradation evaluator 20 for calculating the display brightness
in a certain window displayed on the screen of a display unit and a
display controller 30 for controlling the screen brightness of the
display unit according to the display brightness in the certain
window, calculated by the gray scale gradation evaluator 20, is
provided for.
Inventors: |
Kawano, Seiichi; (Kanagawa,
JP) |
Correspondence
Address: |
IBM CORPORATION
PO BOX 12195
DEPT 9CCA, BLDG 002
RESEARCH TRIANGLE PARK
NC
27709
US
|
Assignee: |
International Business Machines
Corporation
Armonk
NY
|
Family ID: |
18745132 |
Appl. No.: |
10/722084 |
Filed: |
November 25, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10722084 |
Nov 25, 2003 |
|
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|
09938221 |
Aug 23, 2001 |
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Current U.S.
Class: |
345/589 |
Current CPC
Class: |
G09G 5/14 20130101; G09G
2320/0626 20130101; G06F 9/451 20180201 |
Class at
Publication: |
345/589 |
International
Class: |
G09G 005/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 25, 2000 |
JP |
2000-256539 |
Claims
What is claimed is:
1) A brightness adjusting system, comprising: a display gradation
calculator for calculating the display brightness in a specific
area of an image displayed on the screen of a display unit; and a
brightness adjuster for adjusting the screen brightness of said
display unit according to said display brightness in said specific
area, calculated by said display gradation calculator.
2) The system according to claim 1, wherein said display gradation
calculator calculates the display brightness in said specific area
by converting the gradation of each RGB element in a draw signal of
an image displayed in said specific area to a gray scale
gradation.
3) A brightness controlling method for controlling the screen
brightness of a display unit, wherein said method comprises. a step
of calculating the display brightness in a certain window displayed
on the screen of said display unit; and a step of adjusting the
brightness of the whole screen of said display unit according to
said calculated display brightness.
4) The method according to claim 3, wherein said method further
comprises a step of monitoring the state of each window displayed
on said screen of said display unit so as to detect a focused
window on said screen, and said step of calculating said display
brightness further comprises a step of calculating the display
brightness in said detected focused window.
5) The method according to claim 3 wherein said step of calculating
said display brightness further comprises: a step of obtaining
gradation information of each RGB element in a color displayed in
said window; and a step of converting said obtained gradation of
each RGB element to a gray scale gradation so as to decide said
converted gray scale gradation as the display brightness in said
window.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a technique for adjusting
screen brightness of a display unit and more particularly to
adjusting the display brightness of a screen 5 display.
[0003] 2. Description of the Related Art
[0004] The display brightness of a display unit of electronic
devices (e.g., a personal computer, etc.) is often varied
significantly according to the data that is to be displayed. For
example, when displaying text and data entered and edited while
using an application such as a word processor or spreadsheet
software, the background of the image on the screen is often
displayed using a bright color, such as white. As a result, the
user often lowers the screen brightness so as to make it easy to
read displayed data.
[0005] In other situations, images are often displayed in a
plurality of colors on the screen, and the brightness brightness of
the screen is inherently less. As a result, the user increases the
display brightness of the screen so as to make it easier to watch
the displayed images.
[0006] More particularly, the use of a specific type of display may
also affect the resulting display brightness, and hence the user's
visibility of the images displayed. For instance, for an LCD
(Liquid Crystal Display), the visibility is often low at a dark
display. This is because the pixels of the liquid crystal do not
emit light themselves, unlike a CRT display. Therefore, it is known
that a user of an LCD display must often adjust the brightness to
improve the suer's visibility of the screen images.
[0007] Generally, the LCD is provided with a back-light so as to
improve the visibility of the display. Even some of the
conventional LCDs are enabled to adjust the brightness of the
back-light. Certain of such battery-driven systems, such as lap-top
personal computers, can change the brightness of the back-light
feature automatically in addition to the manual adjustment when the
power supply is switched between an AC power source and a battery
so as to suppress the power consumption of the LCD.
[0008] However, these systems must be operated manually to adjust
the brightness of the back-light so as to improve the display
visibility.
[0009] In each of these situations, it is known that conventional
display units have a function for manually changing the screen
brightness. As a result, a user modifies the rightness 5 while
performing his own visual assessment of the appropriateness of the
brightness. However, it is not known to modify the brightness of
the screen automatically in relation to that which is displayed. It
is known to be problematic where in order to improve the display
brightness for a higher visibility, the user must initiate and
visually adjust the screen brightness manually.
SUMMARY OF THE INVENTION
[0010] Accordingly, there is a need for a display unit of an
electronic device wherein the screen brightness may be controllably
enabled to be adjusted for an improved visibility to a user in
relation to the display brightness.
[0011] It is an object of the present invention to automatically
adjust the screen brightness of a display unit according to the
display brightness, thereby improving the visibility of the screen
to the user viewing the screen display.
[0012] It is a further object of the present-invention to provide a
method for displaying data in a window and controlling the screen
brightness of the display unit according to a method for displaying
data in the window as detected by the present invention.
[0013] According to one aspect of the present invention, the
brightness controlling apparatus of the present invention includes
an evaluator for detecting a feature of a certain window displayed
on the screen of a display unit and a display controller for
controlling the screen brightness of the display unit in relation
to the feature of the certain window, as detected by the
evaluator.
[0014] According to another aspect of the present invention, the
brightness controlling apparatus can control the screen brightness
of an integrated display, a connected display, or an external
display unit connected to the apparatus via a cable, as well as the
screen brightness of a display unit formed unitarily with the
housing of the computer system just like a lap-top PC.
[0015] Operatively, the evaluator of the brightness controlling
apparatus detects the type of the application software being used
to display images in a window and the display controller controls
the screen brightness of the display unit according to the type of
the application software detected by the evaluator. As used herein,
the term "image" is inclusive of but not limited to include images,
text, graphics, pictoral representations, drawings, collages,
assemblies of works, alphanumeric representations, and combinations
of any of the foregoing.
[0016] The method of the present invention for displaying data in a
window, to be detected by the evaluator may be, for example, a
method for displaying data under the control of a CPU used by such
application software as a word processor, a method for displaying
data under the control of a bus master that does not use a CPU,
which is used to play back a DVD motion picture, etc.
[0017] Furthermore, the evaluator calculates the display brightness
in the window according to a draw signal issued to the window
displayed on the screen of the display unit. The display controller
controls the screen brightness of the display unit according to the
display brightness in the window, as calculated by the
evaluator.
[0018] In this brightness controlling apparatus, the evaluator
detects a feature of a focused window on the screen, selected from
the windows displayed on the screen of this display unit. The
focused window may be, for example, a window ready to accept an
input (active window) in a multi-window environment. The display
controller sets the screen brightness of the display unit in case
the rate of the size of the window whose feature is detected by the
evaluator to the size of the screen of the display unit is over a
certain value.
[0019] In another aspect of the present invention, a brightness
adjusting system is provided for. The brightness adjusting system
includes a display gradation calculating means for calculating the
display brightness in a specific area of an image displayed on the
screen of a display unit and brightness adjusting means for
adjusting the screen brightness of the display unit according to
the display brightness in the specific area, as calculated by the
display gradation calculating means.
[0020] In addition to the display unit employed as an output device
of a computer system, the display unit may also be a unit of any
various display units such as TV sets, monitors, graphical display
units, etc., including units that comprise other a plurality of
displayable areas. In the latter situation, where a screen is
divided into a plurality of areas so as to display data in each of
those divided areas, the visibility can be improved by adjusting
the screen brightness according to the display brightness in the
specific area.
[0021] The display gradation calculating means calculates the
display brightness in the specific area by converting the gradation
of each RGB element in a draw signal of an image displayed in this
specific area to a gray scale gradation.
[0022] Additionally, in another aspect of the present invention, a
computer system having a processing means for executing an
arithmetic operation and a display unit for displaying the result
of the arithmetic operation executed by the processing means is
provided for. The processing means detects the display brightness
in a certain window displayed on the screen of the display unit and
controls the display unit so as to change the screen brightness of
the display unit according to the detected display brightness in
the window such that the display unit changes the screen brightness
under the control of the processing means.
[0023] The processing means is preferably controlled by an
operating system that has a power management function and controls
the display unit with use of the power management function of the
operating system so as to change the screen brightness of the
display unit.
[0024] In a further aspect, the present invention provides a liquid
crystal display unit provided with a liquid crystal display screen
for displaying an image, a back-light for lighting the liquid
crystal display screen, and a brightness controller for controlling
the brightness of the back-light. In the display unit, the
brightness controller receives a brightness control signal
generated according to the display brightness in the specific area,
calculated from the draw signal of an image in the specific area,
selected from the images displayed on the LCD screen so as to
change the brightness of the back-light according to the brightness
control signal.
[0025] In still a further aspect, the present invention provides a
brightness controlling method for controlling the screen brightness
of a display unit. The method comprises a step of calculating a
brightness of the display in a certain window displayed on the
screen of a display unit and a step of adjusting the whole screen
brightness of the display unit according to the calculated display
brightness.
[0026] The brightness controlling method may further include a step
of monitoring the state of each window displayed on the screen of
the display unit so as to detect a focused window on the screen,
and the step of calculating the display brightness may further
include a step of calculating the display brightness of the
detected focused window. Furthermore, the step of calculating the
display brightness may include a step of obtaining gradation
information of each RGB element in a color displayed in a window
and a step of converting the gradation of each obtained RGB element
to a gray scale gradation so as to decide the converted gradation
as the display brightness in the window.
[0027] In a further aspect, the present invention provides a
computer software means for enabling processing of a computer to
execute, or a storage medium for storing the computer software. The
computer software enables the computer to calculate the display
brightness in a certain window displayed on the screen of a display
unit and control the display unit so as to change the screen
brightness of the display unit according to the calculated display
brightness.
[0028] In a further aspect, the processing means for controlling
the display unit so as to change the screen brightness of the
display unit may use the power management function of an operating
system or an independent power source.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Other aspects, features, and advantages of the present
invention will become more fully apparent from the following
detailed description, the appended claims, and the accompanying
drawings in which:
[0030] FIG. 1 is an overall block diagram of a brightness adjusting
system in the embodiment of the present invention;
[0031] FIG. 2 shows a relationship between the display brightness
of a display unit and the screen brightness set by a display
controller;
[0032] FIG. 3 is another relationship between the display
brightness of the display unit and the screen brightness set by the
display controller;
[0033] FIG. 4 is a flowchart for describing the operation of the
embodiment of the present invention;
[0034] FIG. 5 shows how a text is displayed in a certain
window;
[0035] FIG. 6 shows how a motion picture is played back in the
certain window;
[0036] FIG. 7 is an architecture of a computer system with the
Windows.RTM. 2000 installed as an OS with respect to a function for
displaying data on the display unit screen;
[0037] FIG. 8 is a configuration of a brightness adjusting system
in the embodiment of the present invention, realized as the
computer system shown in FIG. 7;
[0038] FIG. 9 is another configuration of the brightness adjusting
system in the embodiment of the present invention, realized as the
computer system shown in FIG. 7; and
[0039] FIG. 10 is still another configuration of the brightness
adjusting system in an embodiment of the present invention.
DETAILED DESCRIPTION
[0040] Hereinafter, the preferred embodiments of the present
invention will be described with reference to the accompanying
drawings.
[0041] The present invention monitors the draw signal of each image
displayed on the screen of a display unit so as to adjust the
screen brightness according to the display brightness in a
predetermined area on the screen. More specifically, the display
brightness is changed according to the color of each displayed
image (hereinafter, to be referred to as the display color).
Consequently, the present invention determines the display
brightness by converting a display color in the predetermined area
to a gray scale value and adjusts the screen brightness of the
display unit itself (e.g., the brightness of the back-light of an
LCD) according to the obtained display brightness, so as to improve
the visibility of the screen to a viewing user.
[0042] The predetermined area of which display brightness is
evaluated may be the present focused window (active window) in the
display unit of a computer controlled by an operating system
(hereinafter, to be referred to as the OS) corresponding to, for
example, a multi-window environment. More specifically, the screen
brightness of the display unit is adjusted according to each
display color in the focused window. FIG. 1 is an overall block
diagram of a brightness adjusting system in a first preferred
embodiment. According to this preferred embodiment, the brightness
adjusting system shown in FIG. 1 is installed in a computer and it
controls the brightness of display means.
[0043] In FIG. 1, reference numeral 10 denotes a window manager,
which manages the windows to be displayed in the multi-window
environment supported by the OS. The window manager also detects a
focused window. Reference numeral 20 denotes a gray scale gradation
evaluator, which converts each RGB element displayed in the focused
window to a gray scale value so as to find the brightness of the
display color. Reference numeral 30 denotes a display controller,
which sets screen brightness of the display unit. Reference numeral
40 denotes a brightness controller, which controls the screen
brightness of the display unit according to the set value of the
display controller 30.
[0044] In the above-described configuration, the window manager 10
is realized by, for example, software-controlled CPU and RAM, as
well as another memory. The window manager 10 obtains a draw signal
for drawing on the display unit screen so as to manage the state of
each window displayed on the screen under the control of the OS.
Concretely, the window manager 10 detects a focused window and
manages such information as the size and display colors of each
window. When a certain window is focused, the window manager 10
inquires of the gray scale gradation evaluator 20 about the display
brightness of the window. The function of the window manager 10 is
supplied as, for example, a function of the OS.
[0045] The gray scale gradation evaluator 20 is realized by, for
example, software-controlled CPU and RAM, as well as another
memory. The evaluator 20 evaluates the display brightness in the
focused window according to the draw signal of the focused window
in response to an inquiry from the window manager 10. This display
brightness evaluation can be done according to the standard, which
is window gradation information calculated according to the
gradation information of a pixel group corresponding to the whole
or part of the window. Concretely, each display color in the window
is recognized as a gradation value of each RGB element and the
gradation value is converted to a gray scale value so as to find a
gray scale gradation of the window. In the gray scale, both hue and
saturation of the display color are lost and only the brightness
remains. Consequently, the display brightness in the window can be
found by converting each display color in the window to a gray
scale value so as to find the gradation.
[0046] In another preferred embodiment, a display unit displays
data in a color wherein the displayed color is configured by RGB
(i.e., a combination of red (R), green (G) and blue (B) pixels).
Consequently, the gradation per pixel, in the most simple example,
is obtained by dividing the sum of color gradations by 3. More
specifically, the present invention performs the following
calculation:
Gradation per pixel (red gradation+green gradation+blue
gradation)/3
[0047] Additionally, the gray scale gradation in a certain window
is obtained by dividing the sum of gradations per pixel by the
number of pixels. More specifically, the present invention performs
the following calculation:
Gray scale gradation=E(gradation per pixel)/number of pixels
[0048] Additionally, where the gradation per pixel is to be
calculated, the above expression may also be corrected by taking
the hue, the color of the display unit screen panel itself, etc.
into consideration. In such a case, a proper parameter is set for
each RGB element. More specifically, in case parameters p1, p2, and
p3 are set for red, green, and blue respectively, the gradation per
pixel is calculated as follows.
Gradation per pixel=(p1.times.red gradation+p2.times.green
gradation+p3.times.blue gradation), where it is assumed that
p1+p2+p3=1.
[0049] The gray scale gradation in a focused window, calculated by
the gray scale gradation evaluator 20 as described above, is sent
to the window manager 10 as parameters denoting the display
brightness of the focused window. When the window display is
bright, high parameter values are sent and when the window display
is dark, low parameter values are sent. Receiving parameters from
the gray scale gradation evaluator 20, the window manager 10 sends
those parameters to the display controller 30.
[0050] The display controller 30 is realized by, for example,
software-controlled CPU and RAM, as well as another memory. The
display controller 30 sets the screen brightness for the display
unit according to the parameters of the display brightness in the
focused window received from the window manager 10. Concretely, the
display controller 30 decreases the screen brightness in case the
parameter values are high (bright display) and increases the screen
brightness in case the parameter values are low (dark display).
[0051] FIG. 2 illustrates a relationship between the display
brightness of the display unit and the screen brightness set by the
display controller 30. In FIG. 2, the vertical axis denotes the
screen brightness and the horizontal axis denotes the display
brightness of the display unit. The dotted line denotes a
relationship between the screen brightness and the display
brightness when the brightness is not adjusted (fixed) and the
solid line denotes a relationship between the screen brightness and
the display brightness when the brightness is adjusted according to
the values set by the display controller 30. In reference to FIG.
2, it will be understood that the screen brightness is lowered in
steps as the display brightness is increased. And, the more the
display brightness is increased, the more the brightness is
lowered.
[0052] FIG. 3 illustrates another example for denoting the
relationship between the display brightness of the display unit and
the screen brightness set by the display controller 30. In
reference to FIG. 3, it will be understood that the screen
brightness is getting low as the display brightness is increased
and the more the display brightness is increased, the more the
brightness is lowered just like in FIG. 2. Additionally, as is
apparent from FIG. 3, that the more the display brightness is
lowered, the more the brightness is increased.
[0053] As described above, various relationships can be taken for
between the display brightness of the display unit and the screen
brightness set by the display controller 30 in case the screen
brightness is lowered as the display brightness is increased and
increased as the display brightness is decreased (to go low to the
right in FIGS. 2 and 3). Actually, however, the relationship should
preferably be set according to the display unit type (LCD, CRT
display, etc.), the display characteristics, etc.
[0054] The brightness controlling apparatus 40 is a hardware
component for controlling the actual screen brightness by
controlling the operation power of the display unit. The
controlling apparatus 40 increases/decreases the screen brightness
under the control of the display controller 30. When the display
unit is an LCD, the brightness controlling apparatus 40 adjusts the
brightness by controlling the power to the back-light.
[0055] FIG. 4 is a flowchart for describing the operation of the
brightness adjusting system in this embodiment.
[0056] In FIG. 4, the window manager 10 obtains a draw signal
issued to the display unit screen in its initial state so as to
monitor each window displayed on the screen (step 401). In case the
focused window is changed to another, the window manager 10 detects
the display color of the window and inquires of the gray scale
gradation evaluator 20 about the display brightness of the window
(steps 402 and 403). Were the focused window changed to another,
control thereby goes to processings in and after step 402. The
window manager 10 may also start the processings in and after step
403 in case it detects an operation predetermined by the user. The
user-predetermined operation may be booting, suspend resuming,
Windows.RTM. 2000 (.RTM.trademark of Microsoft Corp., USA) display
device switching, etc.
[0057] Next, the window manager 10 requests the display controller
30 to adjust the screen brightness of the display unit as needed
according to the parameters of the display brightness of the
focused window (steps 404 and 405). The parameters are returned
from the gray scale gradation evaluator 20. In response to the
request, the display controller 30 controls the brightness
controlling apparatus 40 so as to adjust the screen brightness of
the display unit (step 406).
[0058] In this particular embodiment, the screen brightness is
adjusted according to the display brightness in a specific area,
which is the focused window selected from the windows displayed on
the screen of the display unit as described above, thereby
controlling the display brightness on the whole screen.
[0059] FIG. 5 illustrates how a text is displayed by the Acrobat
Reader.TM. of Adobe Inc., USA. As shown in FIG. 5, were text and
data can be entered, edited, and displayed, the background is often
displayed in white. Consequently, the window display becomes
bright. In case the window is focused, therefore, the screen
brightness of the display unit is lowered so as to darken the
display of the whole screen for easier recognition of the
display.
[0060] FIG. 6 illustrates how motion picture playback software
plays back a motion picture. The motion picture is displayed in
monochrome in FIG. 6. Generally, however, many colors are used to
display such a motion picture, so the window display becomes
comparatively dark. (In FIG. 6, the motion picture is displayed in
monochrome, so the display is apparently darker than in FIG. 5.) In
case the window is focused, therefore, the screen brightness of the
display unit is increased so as to make the whole screen display
brighter for easier recognition.
[0061] While the window manager 10 decides whether to adjust the
screen brightness of the display unit according to only the display
brightness of the focused window in the above embodiment, the size
of the focused window may also be taken into consideration for the
decision. Concretely, in case the rate of the focused window size
to the display unit screen size is over a certain value (e.g., 1/4
of the whole screen or over), the screen brightness is adjusted.
This is because changes of the screen brightness are considered to
be less effective for improving the visibility in case the focused
window size is small.
[0062] Furthermore, in the above embodiment, the screen brightness
is adjusted according to the display brightness in the window
regardless of the software type displayed in the window. However,
the screen brightness may also be adjusted according to the
software type displayed in the window; there is no need to find the
display brightness in the window in this case. Concretely, such
software as word processor and spreadsheet software that generally
uses a bright display window with a bright background is registered
beforehand, so that the screen brightness can be adjusted
immediately after the window in which the registered software is to
run is focused. In this case, the window manager manages the types
of the application software, thereby it can decide whether to need
brightness adjustment by referring to this information.
[0063] Furthermore, the screen brightness can also be adjusted
according to a method for displaying data on the display unit.
Concretely, it is possible to control the display unit so that such
data as a DVD motion picture is high-lighted when it is played back
by the bus master without using the CPU and in other cases, data is
low-lighted. In this case, the information held in the display
driver and/or the graphic chip can be used to change the
brightness.
[0064] Next, a description will be made for the brightness
adjusting system in this embodiment. The system is realized as a
computer system in which the Windows.RTM. 2000 (OS of Microsoft
Corp., USA) is installed.
[0065] FIG. 7 is an architecture of a computer system, which is
related to a function for displaying data on a display unit. The
Windows.RTM. 2000 is installed in the computer system. The computer
architecture shown in FIG. 7 uses an LCD as the display unit.
[0066] In FIG. 7, the window application in the application layer
is already started up and it displays windows on the desk top.
[0067] The OS/device driver layer includes the Win32K, which is a
kernel module; the GDI (Graphics Driver Interface) 32 and the
DirectDraw for converting a command received from the window
application to an instruction so as to be interpreted by a graphic
processing device driver respectively; the I/O manager, which is an
input/output control module; a power manager, which is a power
source management/control module; an ACPI driver for controlling
power saving on the basis of the ACPI (Advanced Configuration and
Power Interface); and a display driver for controlling a graphic
chip. The Win32K includes a window manager and a graphic engine
(GDI).
[0068] The BIOS layer includes the ACPI BIOS corresponding to the
ACPI.
[0069] The hardware layer includes a graphic chip for displaying
images on the LCD screen and a back-light brightness controller,
which is a logic circuit for controlling the back-light of the
LCD.
[0070] In the architecture shown in FIG. 7, a command issued by the
window application is passed to the display driver via the GDI32,
the DirectDraw, the Win32K etc. The display driver then controls
the graphic chip according to the received command and displays a
predetermined image on the LCD screen. On the other hand, in case
the Win32K sends a control instruction to the ACPI driver via the
power manager, the ACPI driver controls the back-light brightness
controller via the ACPI BIOS so as to change the brightness of the
LCD back-light.
[0071] FIG. 8 shows a configuration of a brightness adjusting
system in this embodiment. The brightness adjusting system is
realized as the computer system shown in FIG. 7.
[0072] In FIG. 8, the Win32K operates as the window controller 10
and the power manager operates as the display controller 30 in the
OS/device driver layer. The OS/device driver layer is also provided
newly with a white balance evaluation engine used as a module for
realizing the function of the gray scale gradation evaluator 20.
Furthermore, the back-light brightness controller operates as the
brightness controlling apparatus 40 in this configuration.
[0073] More specifically, in case a certain window is focused by
the user, the Win32K recognizes the window and the white balance
evaluation engine finds the display brightness of the focused
window. Then, the evaluation engine issues an LCD control
instruction to the power manager. The power manager then sends a
control signal to the back-light brightness controller via the ACPI
driver and the ACPI BIOS. The back-light brightness controller thus
adjusts the brightness of the LCD back-light.
[0074] FIG. 9 shows another configuration of the brightness
adjusting system in this embodiment. The brightness adjusting
system is realized as the computer system shown in FIG. 7.,
[0075] In FIG. 9, the graphic chip operates as the window
controller 10, the gray scale gradation evaluator 20, and the
display controller 30. And, the back-light brightness controller
operates as the brightness controlling apparatus 40.
[0076] More specifically, in case a certain window is focused by
the user while the desk top state is held in the video buffer
(memory) of the graphic chip, the state change of the desk top is
detected, the display brightness of the window is evaluated, and
then a control signal is sent to the back-light brightness
controller according to the evaluated display brightness. Then, the
back-light brightness controller adjusts the brightness of the LCD
back-light.
[0077] FIG. 10 shows still another configuration of the brightness
adjusting system in this embodiment. The brightness adjusting
system is also realized as the computer system shown in FIG. 7.
[0078] In FIG. 9, a filter driver is newly added as a module for
realizing the functions of the window controller 10, the gray scale
gradation evaluator 20, and the display controller 30. And, the
back-light brightness controller operates as the brightness
controlling apparatus 40.
[0079] The filter driver obtains a draw signal to be sent from the
Win32K to the display driver so as to check the state of the desk
top. In case a certain window is focused by the user, the filter
driver detects the state change of the desk top and evaluates the
display brightness of the focused window, then sends a control
signal to the back-light brightness controller according to the
evaluated brightness. The back-light brightness controller thus
adjusts the brightness of the LCD back-light.
[0080] While a description has been made for a brightness adjusting
system to be realized as a computer system with Windows.RTM. 2000
installed therein as an OS in this embodiment, the present
invention does not limit the brightness adjusting system only to
the embodiment, of course. Especially, in case the brightness of
the display unit is adjusted without using any existing function of
the OS as described with reference to FIGS. 9 and 10, it is easy to
combine various operating systems (OS) to adjust the
brightness.
[0081] While the screen brightness of the display unit of the
computer system is adjusted according to the display brightness of
a focused window in a multi-window environment in the above
embodiment, the present invention is not limited only to that;
because it is already known well that the brightness of such
display means as a CRT, a plasma display, etc. can be changed under
the control of the computer system body, the technique for
adjusting the screen brightness according to the present invention
can also be used for any display unit employed as other various
display means. For example, some TV sets can divide the screen into
a plurality areas so as to display a plurality of software in those
areas simultaneously. In such a case, a focused display area is
selected from those display areas corresponding to a software
respectively and the display brightness in the display area is
found, thereby adjusting the screen brightness to decide the
appropriate brightness for the display area.
[0082] In this case, the focused display area may be a display area
having the largest dedicated area on the screen and a display area
in which an image corresponding to an output voice is
displayed.
[0083] As described above, according to the present invention, the
screen brightness of a display unit can be adjusted automatically
according to the display brightness so as to improve the visibility
of the display screen.
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