JPH11119877A - Display control method and information processing device - Google Patents

Abstract

(57) Abstract: The present invention relates to a display control method and an information processing apparatus, and suppresses power consumption without requiring complicated operations and without making display on a display unit difficult to view. The purpose is to be able to play. SOLUTION: In the display device, even during an operation other than the brightness adjustment operation, the brightness of the display unit having the brightness adjustment function is gradually reduced from the maximum brightness value to the minimum brightness value with the passage of time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a display control method and an information processing apparatus, and more particularly to a display control method suitable for a display unit driven by a battery and an information processing apparatus using such a display control method. In recent years, portable information processing apparatuses have been frequently used. Portable information processing devices represented by notebook personal computers and portable communication devices are:
Since the battery operates as a power source when it is carried, it is required to minimize power consumption in order to extend the life of the battery. Conventionally, in order to suppress power consumption, the clock frequency of a central processing unit (CPU) in an information processing apparatus is reduced, a motor for rotating a magnetic disk or the like as a storage medium is stopped, or a liquid crystal display (LCD) is used. ) The brightness of the backlight is reduced. However, depending on the state of use of the information processing device, there is an inconvenience that the processing speed is reduced or the usability of the information processing device is reduced due to measures for suppressing the power consumption.
A measure that does not cause inconvenience is desired.

[0002]

2. Description of the Related Art When an LCD is used as a display unit, it is desirable to provide a backlight unit so that the liquid crystal display can be easily viewed. However, when the backlight portion is provided, power consumption required for display increases, and the life of the battery is shortened in a portable information processing device using a battery as a power supply. Therefore, conventionally, the user manually adjusts the luminance of the display unit in consideration of the life of the battery, or forcibly sets the luminance of the display unit to the minimum luminance value. However, when the former method is used, it is necessary for the user to always manually adjust the brightness of the display unit while paying attention to the life of the battery, and the operation of the information processing apparatus is complicated. On the other hand, when the latter method is used, there is a conflicting problem that the display is difficult to see when the minimum luminance value is low, and the effect of suppressing power consumption is small when the minimum luminance value is relatively high.

[0003]

Therefore, conventionally, when the former method is used, the operation of the information processing apparatus becomes complicated,
There was a problem that operability was poor. Also, when the latter method is used, the display is difficult to see when the minimum luminance value is low, and the effect of suppressing power consumption is small when the minimum luminance value is relatively high, so that the display is easy to see and the power consumption is reduced. There was also a problem that it could not be done.

On the other hand, for example, in Japanese Patent Laid-Open No. Hei 5-188869, if there is no access to the information processing apparatus for a predetermined time,
There has been proposed a method of sequentially reducing the luminance of the display unit and finally turning off the display unit. However, in the case of the proposed method, when the information processing apparatus is accessed, the brightness of the display unit is automatically returned to the maximum brightness value. Therefore, there is a problem similar to the case of the latter method. That is, when the maximum luminance value is set relatively small, the display is difficult to see, and when the maximum luminance value is set high, the power consumption cannot be reduced.

Therefore, the present invention provides a display control method and an information processing apparatus capable of suppressing power consumption without requiring complicated operations and making display on a display unit difficult to view. The purpose is to provide.

[0006]

The object of the present invention is to provide a display device according to claim 1, wherein the luminance of the display unit having the luminance adjustment function is changed from the maximum luminance value even during an operation other than the luminance adjustment operation. This is achieved by a display control method that includes a luminance adjustment step of gradually decreasing to a minimum luminance value over time.

According to a second aspect of the present invention, in the first aspect, a setting step of setting at least one of the maximum luminance value and the minimum luminance value is further included. According to a third aspect of the present invention, in the first or second aspect, the method further includes an updating step of automatically updating the minimum luminance value to a luminance value at the time of a luminance adjustment operation for increasing the luminance of the display unit.

[0010] In the invention described in claim 4, in any one of claims 1 to 3, the brightness adjusting step reduces the brightness of the display unit according to a linear or non-linear function. According to a fifth aspect of the present invention, in any one of the first to fourth aspects, in the brightness adjusting step, the brightness of the display unit is reduced only when the display unit is driven by a battery.

According to a sixth aspect of the present invention, in any one of the first to fourth aspects, the brightness adjusting step reduces the brightness of the display unit when the remaining amount of a battery for driving the display unit falls below a predetermined value. Let it. In the invention described in claim 7, in any one of claims 1 to 4, the brightness adjusting step includes the step of reducing the brightness of the display unit to the minimum brightness value when the display unit is driven by a drive source other than a battery. Fixed to a larger luminance value.

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the display unit includes a liquid crystal display having a backlight unit, a plasma display panel (PD).
P) or CRT. The above object is achieved by providing a display unit having a brightness adjustment function according to claim 9 and gradually changing the brightness of the display unit from the maximum brightness value to the minimum brightness value over time even during an operation other than the brightness adjustment operation. This is also achieved by an information processing apparatus having a brightness control unit for reducing the number of pixels. In the invention according to claim 10, in claim 8,
There is further provided setting means for setting at least one of the maximum luminance value and the minimum luminance value.

In the invention according to claim 11, in claim 9 or 10, the brightness control unit automatically updates the minimum brightness value to a brightness value at the time of a brightness adjustment operation for increasing the brightness of the display unit. Including means. According to a twelfth aspect of the present invention, in any one of the ninth to eleventh aspects, the brightness control unit reduces the brightness of the display unit according to a linear or non-linear function.

According to the invention of claim 13, in claims 9 to 1,
2. In any one of the above items 2, further comprising control means for controlling the brightness control unit so as to reduce the brightness of the display unit only when the display unit is driven by a battery. According to a fourteenth aspect of the present invention, in any one of the ninth to twelfth aspects, the luminance control unit controls the luminance control unit to decrease the luminance of the display unit when a remaining amount of a battery for driving the display unit falls below a predetermined value. Control means for performing the operation.

[0013] In the invention according to claim 15, claims 9 to 1 are provided.
In any one of the above, in the state where the display unit is driven by a drive source other than a battery, control means for controlling the luminance control unit so as to fix the luminance of the display unit to a luminance value larger than the minimum luminance value. Is further provided. According to a sixteenth aspect, in any one of the ninth to fifteenth aspects, the display unit is any one of a liquid crystal display having a backlight unit, a plasma display panel (PDP), and a CRT.

According to the first and ninth aspects of the present invention, power consumption can be suppressed without requiring a complicated operation and without making the display on the display unit difficult to see. According to the second and tenth aspects of the present invention, the maximum luminance value and the minimum luminance value can be arbitrarily set according to the user's preference.

According to the third and eleventh aspects of the present invention, the minimum luminance value can be automatically set according to the user's preference. According to the fourth and twelfth aspects of the present invention, the decrease in the brightness of the display unit can be made inconspicuous to human eyes. According to the invention of claims 5 and 13, the life of the battery can be effectively extended.

According to the sixth and fourteenth aspects of the present invention, it is possible to always provide an easy-to-read display according to the life of the battery. According to the seventh and fifteenth aspects, when the battery is not used as the driving source, the brightness of the display unit can be set with priority given to the ease of display. Claim 8
According to the inventions described in (16) and (16), it is possible to perform easy-to-view display on various display units with reduced power consumption.

Therefore, according to the present invention, it is possible to suppress the power consumption without requiring a complicated operation and without making the display on the display unit difficult to view.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

[0019]

FIG. 1 is a block diagram showing a main part of a first embodiment of an information processing apparatus according to the present invention. The first embodiment of the information processing apparatus employs the first embodiment of the display control method according to the present invention. In the first embodiment of the information processing apparatus, the present invention is applied to a portable information processing apparatus. The portable information processing device is, for example, a notebook personal computer, a portable communication terminal, or the like.

In FIG. 1, the information processing apparatus generally includes a display unit 1, a brightness control unit 3, and an information processing unit 4. The display unit 1 includes an LCD, a PDP, a CRT, or the like, and has a brightness adjustment function. The display unit 1 displays the display information from the information processing unit 4 based on the luminance information from the luminance control unit 3. The brightness control unit 3 includes a setting unit including buttons, knobs, and keys for adjusting brightness, and a control unit including a CPU and the like.

The control section of the brightness control section 3 supplies brightness information corresponding to the brightness value set from the information processing section 4 to the display section 1 and changes the brightness of the display section 1 to the maximum brightness value at a predetermined transition time. Has a function of supplying the display unit 1 with luminance information for automatically reducing the luminance value from the minimum luminance value to the minimum luminance value. When an operation of increasing the luminance is performed by the setting unit of the luminance control unit 3, the operation is notified to the information processing unit 4, and the control unit of the luminance control unit 3 responds to the luminance setting information from the information processing unit 4. It also has a function of automatically updating the minimum luminance value to the luminance value at the time of this operation.

The information processing unit 4 supplies display information to the display unit 1 based on an input from an input device (not shown) such as a keyboard, and relates to a luminance value set from the input device or the setting unit. The luminance setting information is supplied to the luminance control unit 3. The maximum luminance value and the minimum luminance value may be set in advance, or may be set in the luminance control unit 3 via the information processing device 4 based on an input from the input device. Further, the predetermined transition time may be set in advance, or may be set in the brightness control unit 3 via the information processing device 4 based on an input from the input device.

The display unit 1 and the information processing unit 4 may have known configurations. This embodiment is characterized in the processing of the control unit of the brightness control unit 3. 2 and 3 are diagrams for explaining the operation of the brightness control unit 3, respectively. 2 and 3, the vertical axis indicates a luminance value displayed on the display unit 1 based on the luminance information output from the luminance control unit 3, and the horizontal axis indicates time. K1 indicates the maximum luminance value, and K2 indicates the minimum luminance value.

FIG. 2 shows the luminance when the setting section of the luminance control section 3 is not operated. In this case, the brightness of the display unit 1 is
Regardless of the operation of the input device, that is, regardless of whether or not the information processing unit 4 is accessed, the brightness decreases to the minimum brightness time K2 in a predetermined transition time T1 from time ta to time tb. For example, the time ta corresponds to a point in time when the information processing apparatus is turned on. As described above, since the brightness of the display unit 1 automatically decreases gradually with the lapse of time, the power consumption of the display unit 1 is gradually reduced without giving the user discomfort or discomfort such as making the display difficult to see. Can be reduced to

FIG. 3 shows the luminance when the setting section of the luminance control section 3 is operated. In this case, regardless of the presence or absence of access to the information processing unit 4, the brightness of the display unit 1 gradually decreases from the time ta, and at the time tc, the user senses that the brightness has decreased too much, and It is assumed that the luminance value has been increased to K3. It is assumed that the luminance value is K2A when the luminance value is increased to K3 by the setting unit, that is, immediately before the luminance value is increased. The minimum luminance value set in the control unit of the luminance control unit 3 is updated to this luminance value K2A. Therefore, time tc
Thereafter, the luminance of the display unit 1 gradually decreases from the luminance value K2A, and decreases to the minimum luminance value K2A updated by the time tb '.

As described above, when the user performs an operation of increasing the luminance, the luminance value does not decrease to a value smaller than the luminance value at the time of this operation. For this reason, the display is performed at the minimum luminance value according to the user's preference, and the power consumption of the display unit 1 is gradually reduced without giving the user discomfort or discomfort such as making the display difficult to see. Can be done. Next, a description will be given of a second embodiment of the information processing apparatus according to the present invention. FIG.
FIG. 9 is a block diagram illustrating a main part of a second embodiment of the information processing apparatus. The second embodiment of the information processing apparatus employs the second embodiment of the display control method according to the present invention. Further, in the second embodiment of the information processing apparatus, the present invention is applied to an L type having a backlight unit.
It is applied to a portable information processing device using a CD. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

In FIG. 4, the display unit 1 is an LCD 11
And a backlight unit 12. The backlight section 12 has a fluorescent tube 13 and a fluorescent tube power supply 14. The brightness control unit 3 includes a control unit 31 including a CPU or the like and having a memory 31a,
The setting unit 32 includes knobs, keys, and the like. The information processing unit 4 is connected to an input / output (I / O)
An interface 41, a CPU 42, a memory 43,
The display control unit 44 has a known configuration. The control unit 31 is connected to the fluorescent tube power supply 14. Setting unit 32
Are connected to the control unit 31. Further, the setting unit 32 and the keyboard 7 are connected to the I / O interface 41, respectively.
1 is connected. The display control unit 44 is connected to the LCD 11.

The control unit 31 transmits the luminance information to the fluorescent tube power supply 14.
To control the brightness of the fluorescent tube 13. For example, when the luminance of the fluorescent tube 13 is controlled by the output voltage of the fluorescent tube power supply 14, the fluorescent tube power supply 14 is digital / analog (D / A
A) It can be composed of a converter. The LCD 11 performs display based on display information obtained from the display control unit 44, and the brightness of the display is controlled by the fluorescent tube 13.

The memory 31a of the control unit 31 stores the maximum luminance value, the minimum luminance value, a predetermined transition time, a function used for gradually decreasing the luminance value, and the like. FIG.
6 is a diagram illustrating a function used when the luminance value is gradually reduced. 5 and 6, the vertical axis indicates luminance,
The horizontal axis indicates time. FIG. 5 shows a case where the function is linear, and the inclination can be set arbitrarily. On the other hand, FIG. 6 shows a case where the function is non-linear, and in this case also, the curve can be set arbitrarily. Further, even if one function to be used is stored in the memory 31a, a plurality of functions are stored in the memory 7a.
May be selected in response to an instruction from the user.

Information input from the keyboard 7 or information input from an external device is supplied to the CPU 42 via the I / O interface 41 in the information processing unit 4, and display information is supplied from the CPU 42 via the display control unit 44. LCD1
1 is supplied. When a luminance value is set from the keyboard 7, the luminance setting information relating to this luminance value is set to CP.
It is supplied to the controller 31 via the I / O interface 41 under the control of U42. When the luminance value is set by operating the setting unit 32, a notification regarding this operation is sent from the setting unit 32 to the CPU 42 via the I / O interface 41.
The CPU 42 supplies the brightness setting information corresponding to the notification to the control unit 31 via the I / O interface 41. For example, the memory 43 includes a ROM that stores a program to be executed by the CPU 42 and a RAM that stores an intermediate result of an operation performed by the CPU 42 and the like. Display control unit 44
Controls the display on the LCD 11 according to the set horizontal and vertical scanning frequencies under the control of the CPU 42.

It goes without saying that the setting section 32 may be omitted and the function of the setting section 32 may be provided to the keyboard 7. FIG. 7 is a flowchart illustrating the operation of the control unit 31. In the figure, a step S1 sets an initial luminance value, that is, a maximum luminance value in the memory 31a based on the luminance setting information from the information processing section 4. A step S2 decides whether or not to lower the luminance value based on the function stored in the memory 31a. If the decision result in the step S2 is NO, a step S3 decides whether or not the luminance has been adjusted by the operation of the setting unit 32. If the decision result in the step S3 is NO, the process returns to the step S2.

If the decision result in the step S2 is YES, a step S4 decides whether or not the luminance value is the minimum luminance value stored in the memory 31a, and the decision result is YES.
, The process proceeds to step S3. On the other hand, if the decision result in the step S4 is NO, a step S5 reduces the luminance according to the function stored in the memory 31a as shown in FIG. 5 or 6, and the process proceeds to the step S3.

If the decision result in the step S3 is YES, a minimum luminance value stored in the memory 31a is automatically updated to a current luminance value in a step S6. Step S7
Increases the brightness to the brightness value set by the user according to the operation of the setting unit 32, and then the process returns to step S2. In step S2, instead of determining whether to decrease the luminance value based on the function stored in the memory 31a, the luminance value is decreased based on power supply information supplied to the I / O interface 41 from an external device. It may be determined whether or not this is the case.

In a first modification of the second embodiment, step S
In 2, it is determined whether to lower the brightness value based on whether or not the power source of the LCD 11, that is, the power source of the information processing apparatus is a battery. A. Is the power supply of the information processing device a battery? C. The power source can be detected by a known method. Therefore, in this modification, it is determined whether or not the brightness value is reduced by determining whether or not the power supply is a battery based on the power supply information supplied to the I / O interface 41 from the external device.

In a second modification of the second embodiment, step S
In 2, it is determined whether or not to lower the brightness value based on whether or not the power source of the LCD 11, that is, the power source of the information processing device is a battery and the remaining amount of the battery is equal to or less than a predetermined value. The remaining amount of the battery used as the power source of the information processing device can be detected by a known method. Therefore, in the present modification, it is determined whether or not the remaining amount of the battery used as the power supply is equal to or less than a predetermined value based on the power supply information supplied to the I / O interface 41 from the external device. It is determined whether or not to lower the brightness value.

In the third modification of the second embodiment, step S
2, the power supply of the LCD 11, that is, the power supply of the information processing apparatus is A. C. It is determined whether to decrease the luminance value based on whether the power is supplied. A. Is the power supply of the information processing device a battery? C. The power source can be detected by a known method as described above. Therefore, in the present modification, the power supply is set to A.O. based on the power supply information supplied to the I / O interface 41 from the external device. C. By determining whether or not the power source is used, it is determined whether or not to lower the luminance value.

In this case, step S2 shown in FIG. 7 includes steps S21 and S22 shown in FIG. Step S21 is as follows. C. It is determined whether or not the power source is the power source based on the power source information. If the determination result is NO, the process proceeds to step S4. On the other hand, if the decision result in the step S21 is YES, a. C. Since the power consumption is not a problem during the use of the power supply, in step S22, the luminance is fixed to a luminance value larger than the minimum luminance value stored in the memory 31a, and the process proceeds to step S3.

In the fourth modified example of the second embodiment, step S
2, the power source of the LCD 11, that is, the power source of the information processing apparatus is a battery, and it is determined whether to lower the brightness value based on whether or not the remaining amount of the battery is equal to or less than a predetermined value. When the remaining amount becomes equal to or less than the predetermined value, the minimum brightness value is updated to a smaller value, thereby preventing the battery with a small remaining amount from being consumed. The remaining amount of the battery used as the power source of the information processing device can be detected by a known method as described above. Therefore, in the present modification, it is determined whether or not the remaining amount of the battery used as the power supply is equal to or less than a predetermined value based on the power supply information supplied to the I / O interface 41 from the external device. Determine whether to lower the brightness value,
When the remaining amount of the battery becomes equal to or less than a predetermined value, the minimum brightness value is updated to a smaller value.

In this case, step S2 shown in FIG. 7 includes steps S21 to S24 shown in FIG. 9, the same steps as those in FIG. 8 are denoted by the same reference numerals, and a description thereof will be omitted. In the case of FIG. 9, if the decision result in the step S21 is NO, a step S23 decides whether or not the remaining amount of the battery is below a predetermined value based on the power supply information.
If so, the process proceeds to step S4. On the other hand, step S
If the decision result in the step 23 is YES, a step S24 comprises:
The minimum brightness value stored in the memory 31a is updated to a smaller value, and then the process proceeds to step S4.

FIG. 10 is a diagram for explaining a change in luminance in a fourth modification of the second embodiment. In the figure, the vertical axis indicates luminance, and the horizontal axis indicates time. Here, for convenience of explanation,
At time tx when the brightness gradually decreases from the maximum brightness value K1 to the minimum brightness value K2 according to the non-linear function, the power supply of the information processing device is switched from the battery to A.V. C. It is assumed that the power has been switched. Further, it is assumed that the remaining amount of the battery has become equal to or less than a predetermined value at time ty while the battery is being used as a power source of the information processing apparatus. In the present modification, as described with reference to FIG. 9, at time tx, the luminance is fixed to the luminance value K3 (K3> K2), and at time ty
In, the minimum luminance value K2 is updated to a luminance value K4 (K4 <K2).

The present invention has been described with reference to the embodiments.
The present invention is not limited to the above embodiments, and it goes without saying that various modifications and improvements can be made within the scope of the present invention.

[0042]

According to the first and ninth aspects of the present invention, the power consumption can be suppressed without requiring a complicated operation and without making the display on the display unit difficult to see. . According to the second and tenth aspects of the present invention, the maximum luminance value and the minimum luminance value can be arbitrarily set according to the user's preference.

According to the third and eleventh aspects of the invention, the minimum luminance value can be automatically set according to the user's preference. According to the fourth and twelfth aspects of the present invention, the decrease in the brightness of the display unit can be made inconspicuous to human eyes. According to the invention of claims 5 and 13, the life of the battery can be effectively extended.

According to the sixth and fourteenth aspects of the present invention, a display that is always easy to read can be performed according to the life of the battery. According to the seventh and fifteenth aspects, when the battery is not used as the driving source, the brightness of the display unit can be set with priority given to the ease of display. Claim 8
According to the inventions described in (16) and (16), it is possible to perform easy-to-view display on various display units with reduced power consumption.

Therefore, according to the present invention, it is possible to suppress the power consumption without requiring complicated operations and without making the display on the display unit difficult to view.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of a first embodiment of an information processing apparatus according to the present invention.

FIG. 2 is a diagram illustrating luminance when a setting unit of a luminance control unit is not operated.

FIG. 3 is a diagram illustrating luminance when a setting unit of a luminance control unit is operated.

FIG. 4 is a block diagram showing a main part of a second embodiment of the information processing apparatus according to the present invention.

FIG. 5 is a diagram showing a linear function used for gradually decreasing a luminance value.

FIG. 6 is a diagram illustrating a non-linear function used when gradually decreasing a luminance value.

FIG. 7 is a flowchart illustrating an operation of a control unit.

FIG. 8 is a flowchart illustrating an operation of a control unit according to a third modification of the second embodiment.

FIG. 9 is a flowchart illustrating an operation of a control unit according to a fourth modification of the second embodiment.

FIG. 10 is a diagram illustrating a change in luminance in a fourth modification of the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Display part 3 Brightness control part 4 Information processing part 7 Keyboard 31 Control part 31a Memory 32 Setting part 42 CPU 43 Memory

Front page continued (51) Int.Cl. ⁶ identifications FI G09G 3/18 G09G 3/20 K 3/20 5/00 530Z 5/00 530 550B 550 5/10 B 5/10 G06F 1/00 333D

Claims (16)

[Claims] In a display device, a brightness adjustment step of gradually reducing the brightness of a display unit having a brightness adjustment function from a maximum brightness value to a minimum brightness value over time even during an operation other than the brightness adjustment operation is performed. Including, display control method. 2. The display control method according to claim 1, further comprising a setting step of setting at least one of the maximum luminance value and the minimum luminance value. 3. The display control method according to claim 1, further comprising an updating step of automatically updating the minimum luminance value to a luminance value at the time of a luminance adjustment operation for increasing the luminance of the display unit. 4. The display control method according to claim 1, wherein said brightness adjusting step reduces the brightness of said display unit according to a linear or non-linear function. 5. The display control method according to claim 1, wherein said brightness adjusting step reduces the brightness of said display unit only when said display unit is driven by a battery. 6. The display control according to claim 1, wherein in the brightness adjusting step, the brightness of the display unit is reduced when a remaining amount of a battery for driving the display unit becomes equal to or less than a predetermined value. Method. 7. The brightness adjusting step includes fixing the brightness of the display unit to a brightness value larger than the minimum brightness value when the display unit is driven by a drive source other than a battery.
The display control method according to claim 1. 8. The display device according to claim 1, wherein the display unit is one of a liquid crystal display having a backlight unit, a plasma display panel (PDP), and a CRT.
Display control method described in the section. 9. A display unit having a brightness adjustment function, and a brightness control unit for gradually reducing the brightness of the display unit from a maximum brightness value to a minimum brightness value over time even during an operation other than the brightness adjustment operation. An information processing device comprising: 10. The information processing apparatus according to claim 9, further comprising setting means for setting at least one of the maximum luminance value and the minimum luminance value. 11. The information processing apparatus according to claim 9, wherein the brightness control unit includes an update unit that automatically updates the minimum brightness value to a brightness value at the time of a brightness adjustment operation for increasing the brightness of the display unit. apparatus. 12. The brightness control unit according to claim 9, wherein the brightness of the display unit is reduced according to a linear or non-linear function.
12. The information processing device according to any one of items 11 to 11. 13. The apparatus according to claim 9, further comprising control means for controlling said brightness control unit so as to reduce the brightness of said display unit only when said display unit is driven by a battery.
13. The information processing device according to any one of claims 12 to 12. 14. A control unit for controlling the brightness control unit such that the brightness of the display unit is reduced when the remaining amount of a battery for driving the display unit falls below a predetermined value. The information processing apparatus according to any one of claims 1 to 7. 15. A control means for controlling the luminance control unit so that the luminance of the display unit is fixed to a luminance value larger than the minimum luminance value when the display unit is driven by a driving source other than a battery. The information processing apparatus according to claim 9, further comprising: 16. The liquid crystal display having a backlight unit, a plasma display panel (PDP), and the display unit.
The information processing apparatus according to claim 9, wherein the information processing apparatus is any one of a CRT and a CRT.