Information processing device and control method

Abstract

To reduce power consumption without compromising usability.SOLUTION: A power supply circuit is supplied with electric power from a power supply. A luminance control part controls a luminance of a display, and has a first reference value for the case where the power supply type is an external power supply and a second reference value smaller than the first reference value and for the case where the power supply type is a battery, as reference values of a luminance set value representing a set value of the luminance. The luminance set value is set to a user-set value designated by a user in accordance with an operation by the user. When the power supply type is switched from the external power supply to the battery in a state where the user-set value is larger than the second reference value, luminance reduction processing for reducing the luminance setting value to a value between the user-set value and the second reference value is executed. When the power supply type is switched from the battery to the external power supply in a case where the luminance set value is smaller than the first reference value, luminance increase processing for increasing the luminance setting value to a value between the current luminance set value and the first reference value is executed.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] This application relates to an information processing apparatus and a control method, and more particularly, to luminance control of a display.

Background Art

[0002] A portable information processing apparatus such as a notebook personal computer (which may be referred to as a "notebook PC: Personal Computer" in this application) is not always used in an environment where power is constantly supplied from an external power source. Therefore, the information processing apparatus includes a rechargeable battery and consumes the power stored in the battery. The battery life is defined as the period during which the apparatus can continue to operate without receiving power from an external power source, and it is expected to be as long as possible.

[0003] For example, Patent Document 1 describes an information processing apparatus including a rechargeable battery, an AC adapter that supplies power to a predetermined device, a processing priority mode that supplies power from the AC adapter to various devices, a charging mode that shifts various devices to a power saving operation mode and prioritizes power supply from the AC adapter to the battery, and an operation mode switching button that switches between the processing priority mode and the charging mode. The apparatus detects pressing of the operation mode switching button and performs control to switch between the processing priority mode and the charging mode, and also detects the remaining capacity of the battery and performs control to switch between the processing priority mode and the charging mode according to the detected remaining capacity of the battery.

[0004] To increase the battery life, it is conceivable to employ a battery with a large capacity. However, generally, the larger the capacity of the battery, the larger its size tends to be. To meet the portability requirements of the information processing apparatus, it is still important to reduce power consumption. On the other hand, among the devices provided in the information processing apparatus, the power consumption of the display may be larger than that of other devices. In such an information processing apparatus, it is required to reduce the power consumption of the display.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-9538 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] Therefore, it is conceivable to determine the brightness of the display according to the power consumption setting of the information processing apparatus and to provide a function of increasing the brightness to the desired brightness of the user according to the user operation. With this function, it is possible to make the display information on the display easier to see when used in a brighter environment such as outdoors during the day. However, when returning to a darker environment, it is relatively rare for the user to perform an operation to decrease the brightness with respect to the brightness that has been increased once. If the operation is not performed, the high brightness state is maintained, so that power may be wasted. [Means for Solving the Problems]

[0007] The present application has been made to solve the above problems, and an information processing apparatus according to an aspect of the present application includes a power supply circuit to which power is supplied from a power source, and a brightness control unit that controls the brightness of a display. The brightness control unit includes a first reference value when the power source type is an external power source and a second reference value that is smaller than the first reference value and is used when the power source type is a battery, as reference values for a brightness setting value that is a set value of the brightness. The brightness setting value is set to a user setting value specified by the user according to an operation by the user. When the power source type switches from an external power source to a battery in a state where the user setting value is larger than the second reference value, a brightness reduction process for reducing the brightness setting value to a value between the user setting value and the second reference value is executed. When the power source type switches from a battery to an external power source in a state where the brightness setting value is smaller than the first reference value, a brightness increase process for increasing the brightness setting value to a value between the current brightness setting value and the first reference value is executed.

[0008] In the information processing apparatus described above, when the power supply type switches from the battery to an external power supply, the brightness control unit may increase the brightness setting value in the brightness increase process by an amount smaller than the amount of change related to the decrease in the brightness setting value in the brightness reduction process.

[0009] In the information processing apparatus described above, the brightness control unit may update the second reference value based on the frequency of operations performed by the user for each brightness setting value.

[0010] In the information processing apparatus described above, the second reference value is larger for a power control mode with a larger rated power of the host system, and the brightness control unit may set the brightness setting value to a reference value corresponding to the set of the selected power control mode and the power supply type.

[0011] A control method according to a second aspect of the present application is a control method for an information processing apparatus including a power supply circuit supplied with power from a power supply and a brightness control unit that controls the brightness of a display. The information processing apparatus includes, as reference values for a brightness setting value that is a set value of the brightness, a first reference value when the power supply type is an external power supply, and a second reference value that is smaller than the first reference value and is used when the power supply type is a battery. In response to an operation by the user, the brightness setting value is set to a user setting value designated by the user. When the power supply type switches from an external power supply to a battery while the user setting value is larger than the second reference value, a brightness reduction process is executed to reduce the brightness setting value to a value between the user setting value and the second reference value. When the power supply type switches from a battery to an external power supply while the brightness setting value is smaller than the first reference value, a brightness increase process is executed to increase the brightness setting value to a value between the current brightness setting value and the first reference value.

Advantages of the Invention

[0012] According to the present embodiment, power consumption can be reduced without impairing usability for the user.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0014] <First Embodiment> Hereinafter, embodiments of the present application will be described with reference to the drawings. First, an overview of the information processing apparatus 1 according to the first embodiment of the present application will be described. In the following description, mainly the case where the information processing apparatus 1 is a notebook PC will be taken as an example. However, the information processing apparatus 1 is not necessarily limited to a notebook PC, and may be configured as a tablet terminal device, a smartphone, or the like.

[0015] FIG. 1 is an external view showing an example of the external configuration of the information processing apparatus 1 according to the present embodiment. The information processing apparatus 1 includes two housings 102 and 104. The housings 102 and 104 each have a horizontally long surface that is wider than its height and has a flat shape that is thinner than its height. One side surface of each of the housings 102 and 104 is arranged in parallel in the width direction and engaged with each other using hinges 108a and 108b. One of the housings 102 and 104 is connected to the other so as to be rotatable about the rotation axis A. That is, by making the angle formed by the surfaces of the housings 102 and 104 (hereinafter sometimes referred to as the "opening angle") variable, both of them open and close. An opening angle of 0° or an angle close to 0° (for example, 45° to 60° or less) corresponds to the state where the housings 102 and 104 are closed. An opening angle that is sufficiently large (for example, an angle greater than 45° to 60°) corresponds to the state where the housings 102 and 104 are open. In a state where no external force is applied to the housings 102 and 104, the opening angle is maintained constant.

[0016] The housing 102 includes a lid sensor 42 at a portion away from the rotation axis A. The lid sensor 42 detects the open / closed state of the housings 102 and 104. In the example of FIG. 1, the lid sensor 42 has a magnetic sensor. A permanent magnet 46 is installed on the housing 104 at a position facing the lid sensor 42 when the housings 102 and 104 are closed. When the housings 102 and 104 are closed, the magnetic sensor detects a relatively strong magnetic field because it is close to the permanent magnet. When the housings 102 and 104 are open, the detected magnetic field becomes weaker because the magnetic sensor is away from the permanent magnet. Therefore, the open / closed state of the housings 102 and 104 is determined based on the strength of the detected magnetic field. In the example of FIG. 1, the housing 102 further includes an acceleration sensor 44.

[0017] A keyboard 32k, a touch pad 32t, and a power button 36 are arranged on the surface of the housing 102. An outlet (outlet) 48o is installed on the side surface in the width direction of the housing 102. The outlet 48o has a cavity into which the plug of the AC adapter 48 can be inserted, and by fitting with the inserted plug, the position of the plug is fixed in contact with the electrode installed on the inner surface of the cavity. DC power is supplied from the AC adapter 48 to the information processing apparatus 1 via the plug inserted into the outlet 48o.

[0018] The AC adapter 48 is supplied with AC power from a commercial power supply, and converts the supplied AC power into DC power having a constant voltage (for example, 3V to 12V). The display 14 is disposed on the surface of the housing 104. The display 14 covers most of the surface of the housing 104.

[0019] FIG. 2 is a schematic block diagram showing a hardware configuration example of the information processing apparatus 1 according to the present embodiment. The information processing apparatus 1 includes a processor 11, a main memory 12, a video subsystem 13, a display 14, a chipset 21, a BIOS (Basic Input-Output System) memory 22, a storage 23, an audio system 24, a WLAN (Wireless Local Area Network) card 25, a USB (Universal Serial Bus) connector 26, an EC (Embedded Controller) 31, an input device 32, a power circuit 33, a battery 34, a power button 36, a lid sensor 42, and an acceleration sensor 44.

[0020] The processor 11 executes arithmetic processing according to various instructions described in a program, and controls the operation of the entire information processing apparatus 1. As the processor 11, for example, one or more CPUs (Central Processing Unit) may be included. The main memory 12 is a writable memory used as a reading area for a program executed by the processor 11 or a working area for writing processing data of the executed program. The main memory 12 includes, for example, one or more DRAM (Dynamic Random Access Memory) chips. The program includes, for example, an OS (Operating System), a driver for controlling the operation of peripheral devices, various service / utility programs (sometimes referred to as "utilities" in the present application), and application programs (sometimes referred to as "apps" in the present application).

[0021] The processor 11, the main memory 12, and the chipset 21 are the minimum hardware components that make up the host system 110 (Figure 3). In this application, the devices that make up the host system 110 may be collectively referred to as "system devices". The system devices may be configured as an integrated member (e.g., SoC: System-on-Chip). The host system 110 is the core computer system of the information processing apparatus 1. The processor 11 executes a predetermined program and cooperates with the main memory 12 and other hardware to realize the functions of the host system 110. In this application, "executing a program" or "execution of a program" includes the meaning of performing the processing instructed by the instructions described in the program.

[0022] The video subsystem 13 is a subsystem for realizing functions related to image display. The video subsystem 13 includes a video controller (not shown). The video controller performs the processing instructed by the drawing instructions input from the processor 11 and writes the display data obtained by the processing into a video memory (not shown) provided in itself. The video controller reads out the display data written from the video memory and outputs the read display data to the display 14.

[0023] The display 14 displays various display screens based on the display data input from the video subsystem 13. The display 14 may be any type of display, such as an LCD (Liquid Crystal Display), an OLED (Organic Light Emitting Diode) display, etc. The display 14 includes a pixel panel and a power supply video circuit (not shown). The surface of the pixel panel forms a two-dimensional plane, and a plurality of pixels are arranged at regular intervals. Each pixel emits light by the power supplied from the drive circuit.

[0024] The power supply video circuit converts the power supplied from the power supply circuit 33 into drive power for causing light emission with brightness corresponding to the signal value for each pixel indicated by the display data input from the video subsystem 13. An image is represented by the distribution of brightness for each pixel. The power supply video circuit multiplies the generated drive power by a gain to adjust the intensity of the drive power. By adjusting the intensity, the brightness of the image displayed on the display is adjusted. The power supply video circuit outputs the drive power for each pixel after intensity adjustment to the drive circuit. In the power supply video circuit, luminance setting information indicating the correspondence between a preset luminance setting value (which may be referred to as the "luminance setting value" in this application) and a gain is set in advance. The power supply video circuit refers to the luminance setting information, specifies the gain corresponding to the luminance setting value notified from the host system, and adjusts the intensity of the drive power using the specified gain.

[0025] The chipset 21 is connected to one or more peripheral devices and controls the input and output of various types of data. The chipset 21 includes various input / output interfaces and connects devices corresponding to them. The chipset 21 includes controllers corresponding to various input / output methods. The chipset 21 includes a controller related to, for example, any one of USB (Universal Serial Bus), Serial ATA (Advanced Technology Attachment), SPI (Serial Peripheral Interface) bus, PCI (Peripheral Component Interconnect) bus, PCI-Express bus, and LPC (Low Pin Connect) bus, or any combination thereof. In the example of FIG. 2, the peripheral devices connected to the chipset 21 include a BIOS memory 22, a storage 23, an audio system 24, a WLAN card 25, a USB connector 26, and an EC 31 are illustrated.

[0026] The BIOS memory 22 stores system firmware such as BIOS in advance. The BIOS memory 22 may store firmware for controlling the operations of the EC 31 and other devices. The BIOS memory 22 is composed of a rewritable non-volatile memory (for example, EEPROM (Electrically Erasable Programmable Read Only Memory), flash ROM, etc.).

[0027] The storage 23 has an auxiliary storage device that stores various programs and data executed by the processor 11. The storage 23 is composed of a rewritable non-volatile memory. The storage 23 may be any of an SSD (Solid State Drive), HDD (Hard Disk Drive), etc. The audio system 24 performs input, output, and recording of audio data. The audio system 24 may be provided with speakers. The speakers emit sounds based on the audio data input to the self. The audio system 24 may be provided with microphones. The microphones pick up sounds arriving at the self and acquire audio data indicating the picked-up sounds.

[0028] The WLAN (Wireless Local Area Network) card 25 connects to a wireless LAN and performs data communication with other devices directly or indirectly connected to the wireless LAN. The wireless LAN enables transmission and reception of various data between devices according to a predetermined wireless communication method (for example, IEEE802.11). The USB connector 26 is a connector for connecting to a peripheral device to enable input and output of data according to the USB (Universal Serial Bus) standard.

[0029] Regardless of the system state of the host system, EC31 monitors the operating environment and controls the states of various devices (peripheral devices, sensors, etc.). EC31 is independently equipped with a processor, memory, and input / output terminals, and is configured as a microcomputer. To EC31, an input device 32, a power supply circuit 33, a power button 36, a lid sensor 42, an acceleration sensor 44, etc. are connected using its input / output terminals.

[0030] The input device 32 detects the user's operation and outputs an operation signal corresponding to the detected operation to EC31. The above touch pad 32t and keyboard 32k belong to the input device 32. The input device 32 may include a touch sensor. The touch sensor may overlap with the display 14 and be configured as a touch panel.

[0031] The power supply circuit 33 converts the voltage of the DC power supplied from an external power supply via the AC adapter 48 or from the battery 34 into the voltage required for the operation of each device constituting the information processing device 1, and supplies the power having the converted voltage to the device at the supply destination. The power supply circuit 33 controls whether power supply to each device of the information processing device 1 is required or not according to the control of EC31. The power supply circuit 33 includes a converter that converts the voltage of the power supplied to itself, and a charge / discharge unit that charges the battery 34 with the power whose voltage has been converted. The charge / discharge unit charges the battery 34 with the power remaining without being consumed in each device among the power supplied from the AC adapter 48. When power is not supplied from the AC adapter 48, or when the power supplied from the AC adapter 48 is insufficient for the required power, the power discharged from the battery 34 is supplied to each device via the converter. The power supply destinations include, in addition to system devices, the display 14, peripheral devices including EC31.

[0032] The power supply circuit 33 is electrically connected to a power supply terminal installed at the insertion port 48o. DC power is supplied to the power supply circuit 33 from the AC adapter 48 attached to the insertion port 48o via the power supply terminal. The power supply circuit 33 may include a voltage sensor that detects the voltage of the power supply terminal and outputs a voltage detection signal indicating the detected voltage to the EC31. The EC31 can determine whether the type of power supply (which may be referred to as the "power supply type" in this application) that supplies power to the information processing device 1 based on the voltage detection signal input from the voltage sensor is either an external power supply or the battery 34. Whether the power supplied from the external power supply or the power supplied from the battery 34 is consumed depends on whether the AC adapter 48 is attached to the insertion port 48o in a state where DC power can be supplied. The EC31 can determine whether the power supply type is an external power supply or the battery 34, for example, based on whether the voltage indicated by the voltage detection signal is higher than a predetermined voltage reference value. The EC31 notifies the host system 110 of the determined power supply type.

[0033] The battery 34 is stored inside the housing 102. The battery 34 charges the power supplied from the AC adapter 48 by the charge and discharge unit of the power supply circuit, and supplies the charged power to each device via a converter. The battery 34 has a secondary battery that can be charged and discharged. The battery 34 has, for example, a lithium-ion battery. Each time a pressing operation of the power button 36 is received, it controls either power-on (Power ON) or power-off (Power OFF) as the power supply state to the host system 110 of the information processing device 1. When a pressing operation is received, the power button 36 outputs a pressing signal indicating the pressing to the EC31.

[0034] The lid sensor 42 detects the open / closed state of the housings 102 and 104. The lid sensor 42 generates a detection signal indicating the detected open / closed state and outputs it to the EC 31. The EC 31 identifies the open / closed state based on the detection signal input from the lid sensor 42. For example, when the lid sensor 42 is a magnetic sensor, the EC 31 can determine whether the housings 102 and 104 are closed by whether the intensity of the magnetic field indicated by the detection signal is equal to or greater than a predetermined intensity threshold. The EC 31 notifies the host system of the open / closed state information indicating the determined open / closed state. In the following description, the state where the housings 102 and 104 are open may be referred to as the "open state" (lid open), and the state where the housings 102 and 104 are closed may be referred to as the "closed state" (lid closed). The EC 31 notifies the determined open / closed state to the host system 110 via the chipset 21. The open / closed state notified to the host system may be used for controlling the system state.

[0035] The acceleration sensor 44 detects the acceleration applied to itself and outputs an acceleration signal indicating the detected acceleration to the EC 31. The acceleration sensor 44 is, for example, a three-axis sensor. The three-axis sensor can detect accelerations in the axial directions orthogonal to each other in a three-dimensional space. The EC 31 outputs the acceleration signal input from the acceleration sensor 44 to the host system. The acceleration notified to the host system may also be used for controlling the system state.

[0036] Next, a functional configuration example of the information processing apparatus 1 according to the present embodiment will be described. FIG. 3 is a schematic block diagram showing a functional configuration example of the information processing apparatus 1 according to the present embodiment. The host system 110 of the information processing apparatus 1 includes a setting processing unit 112, an operation mode control unit 114, a usage state detection unit 116, and a luminance control unit 118. The setting processing unit 112 sets various parameters in the host system according to user operations. The setting processing unit 112 causes the display 14 to display a setting screen. The setting screen is configured to include parameters that can be set and the set values of the parameters set at that time. The setting processing unit 112 selects a power control mode indicated by an operation signal input via the EC31 from among a plurality of predetermined power control modes. The setting processing unit 112 notifies the selected power control mode to the luminance control unit 118.

[0037] The host system 110 operates according to the selected power control mode. The power consumption of the host system 110 differs for each power control mode. Each individual power control mode is defined using parameters related to the power consumption of the host system 110. The parameters related to the power control mode include the rated power of the CPU (e.g., PL1: Power Limit 1). Generally, the higher the rated power, the higher the power consumption and the higher the processing ability of the host system 110. On the other hand, the lower the rated power, the lower the power consumption and the lower the processing ability of the host system 110.

[0038] The setting processing unit 112 may configure a guidance screen including power source type information indicating the power source type notified from the EC31, and cause the configured guidance screen to be displayed on the display 14. FIG. 4 is a diagram illustrating a setting screen PS01 and a guidance screen TB01 according to the present embodiment. The illustrated setting screen PS01 and guidance screen TB01 each have an elongated shape in which the horizontal width is larger than the vertical height. The setting screen PS01 and the guidance screen TB01 may be arranged at a position in contact with the bottom side of the display area of the display 14. The setting screen PS01 constitutes a slider bar used to select one of the three-level power control modes from the three-level power control mode by a user operation. As the three-level power control modes, an efficiency mode (Best Power Efficient), a balance mode (Balanced), and a performance mode (Best Performance) are arranged in that order from left to right. Among the three-level power control modes, the efficiency mode is the power control mode with the least rated power, and the rated power increases in the order of the efficiency mode, the balance mode, and the performance mode. The guidance screen TB01 is configured as a task bar, and an icon formed by schematizing a combination of a power plug and a battery is represented at the center thereof. This display indicates that the power source type is an external power source.

[0039] The operation mode control unit 114 controls the system state (operation mode) of the host system 110 based on the usage status of the information processing apparatus 1. For each pair of a certain system state 1 and another system state 2, the operation mode control unit 114 presets the transition condition from the source system state 1 to the destination system state 2. The operation mode control unit 114 refers to the transition condition from the current system state 1 to the system state 2, and when the current operation state or usage environment satisfies the transition condition to the system state 2 based on the usage status of the information processing apparatus 1, the operation mode control unit 114 changes the current system state 1 to the system state 2. The operation mode control unit 114 notifies the EC 31 of the system state determined by the control via the chipset 21.

[0040] The system states include, for example, the normal mode, modern standby, hibernation, and power off. The normal mode, hibernation, and power off correspond to the S0 state, S4 state, and S5 state, respectively, among the system states defined by the ACPI (Advanced Configuration and Power Interface) standard. Modern standby is a standby state with less power consumption than the normal mode, but it is a state that extends the S0 state. Modern standby may also be denoted as the S0ix state or S0i3 state. Generally, the power consumption decreases in the order of the normal mode, modern standby, hibernation, and power off.

[0041] The normal mode is the normal system state. In the normal mode, when the display 14 operates and the system state for displaying a display screen according to the display data output from the host system 110 is the normal mode, the luminance control unit 118 performs the luminance control described later. In other system states, since the screen display from the display 14 is stopped, the luminance control unit 118 does not perform the luminance control of the display 14.

[0042] Next, an example of the transition conditions of the system state will be described. The transition conditions from the normal mode to modern standby are, for example, when no operation signal from the input device 32 is detected for a certain period (e.g., 3 to 10 minutes) or more without the display screen changing, when there is no application instructed to start, when the open / closed state of the housings 102 and 104 changes from the open state to the closed state, when the acceleration indicated by the acceleration signal from the acceleration sensor 44 is greater than a predetermined reference value, etc. In modern standby, in addition to the EC 31, some peripheral devices such as the storage 23 and the WLAN card 25 may continue to operate. Also, the host system 110 may wait for an operation signal from the input device 32 via the EC 31 and the chipset 21.

[0043] The transition conditions from modern standby to normal mode include, for example, when an operation signal is input from the input device 32, when a press signal is input from the power button 36, when the open / closed state of the casings 102 and 104 changes from the closed state to the open state, when the acceleration indicated by the acceleration signal from the acceleration sensor 44 is below a predetermined reference value for a predetermined continuous time or more, etc.

[0044] The transition conditions from modern standby to hibernation include, in addition to the case where the measured power consumption is less than or equal to the reference power consumption, when modern standby continues for a certain time (e.g., 10 to 30 minutes) or more, when the time at that point reaches a preset rest time, when sleep is instructed by an operation signal, when the remaining amount of the battery 34 is less than or equal to a predetermined limit value, etc. The transition conditions from normal mode or modern standby to power off include, for example, when a press signal is input from the power button 36, or when a predetermined request is issued from the OS.

[0045] Note that in the modern standby or power off state, since the operation of the host system 110 has stopped, the operation mode control unit 114 is not involved in the transition from the modern standby or power off state to the normal mode. The transition from the power off state to the normal mode is executed by the startup process based on the BIOS. In the transition from modern standby to normal mode, the EC 31 resumes the power supply to the host system 110, loads the image data saved in the storage 23 into the main memory 12, and then starts the OS.

[0046] The usage detection unit 116 detects the usage status of the information processing apparatus 1. The usage detection unit 116 detects the usage status related to the control of the system state, the usage status related to the brightness control, or the change thereof. The usage detection unit 116, for example, includes the input of an operation signal from the input device 32 via the EC 31, the notification of the power supply type from the EC 31, the input of a press signal from the power button 36 via the EC 31, the notification of the opening / closing state information of the housings 102 and 104, the input of an acceleration signal from the acceleration sensor 44 via the EC 31, the change of the display data output to the display 14, and the like. Among them, the operation signal, the press signal, the opening / closing state information, the acceleration signal, etc. are used for the control of the system state. The operation signal and the power supply type information, etc. are used for the brightness control.

[0047] The brightness control unit 118 controls the brightness of the display screen to be displayed on the display 14 according to the usage status of the information processing apparatus 1. The brightness control unit 118 determines a reference value of the brightness setting value based on the power supply type notified from the usage detection unit 116. When the power supply type is the battery 34, the brightness control unit 118 determines a value lower than the reference value of the brightness setting value when the power supply type is an external power supply. This is because when the power supply type is the battery 34, it is necessary to make the display screen displayed on the display 14 darker than when it is an external power supply and reduce the power consumption. Each time the brightness control unit 118 sets the brightness setting value, the brightness control unit 118 notifies the set brightness setting value to the display 14. By notifying the brightness setting value, the brightness control unit 118 causes the screen to be displayed at the brightness corresponding to the brightness setting value.

[0048] The brightness control unit 118 may determine a reference value of the brightness setting value further considering the power control mode notified from the setting processing unit 112. The brightness control unit 118 sets a larger value as the reference value of the brightness setting value for a power control mode with a larger rated power. This is because when improving the processing ability of the host system 110, it is expected that the display 14 will display a screen with a higher brightness. Therefore, a brightness setting table indicating default brightness setting values is preset in the brightness control unit 118 for each set of the power control mode and the power supply type. The brightness control unit 118 refers to the brightness setting table, specifies the brightness setting value corresponding to the set of the instructed power control mode and the notified power supply type, and sets the specified brightness setting value in the display 14.

[0049] FIG. 5 is a diagram showing a setting example of the brightness setting table according to the present embodiment. The brightness setting table is a data table showing default brightness setting values that serve as reference values of the brightness setting value for each set of the power control mode and the power supply type. As the default brightness setting value, a higher value is set for a power control mode with more rated power, and for an external power supply than when the power supply type is the battery 34. In FIG. 5, each row indicates the power supply type, and each column indicates the power control mode. DC described in the column of the power supply type indicates the battery, and AC indicates the external power supply. As the power control mode, an efficiency mode, a balance mode, and a performance mode are listed. The reference values in the case where the power supply type is the battery are set such that LD1 < LD2 < LD3. The reference values in the case where the power supply type is the external power supply are set such that LA1 < LA2 < LA3. For each individual power control mode, the reference values are set such that LD1 < LA1, LD2 < LA2, and LD3 < LA3. However, for the performance mode, LD3 = LA3 may be set.

[0050] Depending on the usage environment and the user's preference, a higher brightness than the brightness determined based on one or both of the power supply type and the power control mode may be desired. For example, outdoors during the day, since the surroundings are bright, it is desirable to brighten the screen displayed on the display. Therefore, the luminance control unit 118 may adjust the luminance setting value according to a predetermined operation. In this application, the luminance setting value adjusted according to the user's operation may be referred to as the "user setting value". For example, each time the luminance control unit 118 detects an operation on a predetermined key on the keyboard 32k (for example, pressing the F6 key), the luminance setting value is increased by a predetermined increase amount. However, when the luminance setting value reaches the preset maximum value, even if the operation is detected, the luminance control unit 118 does not perform the process of further increasing the luminance setting value.

[0051] The luminance control unit 118 monitors the power supply type notified from the usage detection unit 116. When the power supply type is changed from an external power supply to the battery 34, and the luminance setting value at that time is greater than the reference value of the luminance setting value when the power supply type is the battery 34, the luminance setting value at that time is decreased. However, the decreased luminance setting value is set to a value greater than the reference value. Incidentally, when the power supply type is switched from an external power supply to the battery, the process of decreasing the luminance setting value to a value between the user setting value and the reference value when the power supply is the battery 34 may be referred to as the "luminance reduction process".

[0052] In addition, the user may notice the decrease in luminance due to the decrease in the luminance setting value, and may be prompted to perform an operation to increase the luminance setting value again. When the luminance increases due to the operation, the power consumption increases again. Therefore, the amount of change in the luminance setting value when the power supply type is changed from an external power supply to the battery 34 may be, for example, such that the user does not notice the change in luminance. For example, it may be about several percent to 10% of the value range of the luminance setting value.

[0053] Each time the notified power supply type is changed from an external power supply to the battery 34, the luminance control unit 118 may decrease the luminance setting value by a certain amount of change until it reaches the reference value corresponding to the battery 34. The brightness control unit 118 may decrease the amount of change in the brightness setting value due to the change to the battery 34 of the power supply type as the brightness setting value becomes smaller. For example, each time the power supply type is changed to the battery 34, the brightness control unit 118 may decrease the brightness setting value at that time at a constant change rate (for example, 5 to 10%). When decreasing the brightness setting value at a constant change rate, the amount of change in the brightness setting value decreases with each repetition of the decrease in the brightness setting value.

[0054] Next, the relationship between the brightness setting value set by the brightness control unit 118 and the brightness of the screen displayed on the display 14 will be described. The brightness setting value may be the brightness itself, which is a physical quantity, or may be an index value that uniquely corresponds to the brightness. The brightness setting value may be normalized to a real number value that is easily recognizable to the user. The brightness setting value is a real number within a predetermined value range (for example, from 0% to 100%). The larger the brightness setting value, the higher the brightness is indicated. 0% and 100% correspond to the minimum and maximum values of the brightness. As the brightness setting value, values predefined by software such as the OS and the device driver of the display 14 may be used. The brightness control unit 118 may display a setting screen including screen components such as a dial and a slider bar on the display 14 based on this software, and may be able to arbitrarily set the brightness setting value according to the operation.

[0055] As described above, the display 14 supplies driving power having an intensity obtained by multiplying the intensity corresponding to the signal value shown in the display data by the gain corresponding to the brightness setting value to each pixel. As illustrated in FIG. 6, as the brightness setting value increases, the brightness of the displayed image tends to increase. Also, as the brightness setting value increases, the ratio of the increase amount of the brightness to the increase amount of the brightness setting value also increases.

[0056] Next, an example of the transition of the brightness setting value due to a change in the usage situation will be described with reference to FIG. 6. At the beginning of the use of the information processing apparatus 1, the brightness control unit 118 sets, as the initial value LD of the brightness setting value, a reference value of the brightness setting value corresponding to the set of the power control mode and the power supply type. The display screen is displayed on the display 14 at the brightness determined based on the set brightness setting value. Here, assume a case where the user wants to brighten the display screen and performs a predetermined key operation (a. key operation). Each time the brightness control unit 118 detects a key operation, it increases the brightness setting value by a predetermined increase amount. Due to this increase in the brightness setting value, the brightness of the display screen represented on the display 14 increases. The brightness setting value increases each time a key operation is detected until it reaches the maximum value LMAX.

[0057] Thereafter, assume a case where the user disconnects the AC adapter 48 from the information processing apparatus 1 (b. AC / DC switching). At this time, the disconnection of the AC adapter 48 is detected in the EC 31, and the change from the external power supply of the power supply type to the battery 34 is detected. Each time the brightness control unit 118 detects the change from the external power supply of the power supply type to the battery 34, the brightness setting value decreases at a constant rate of change. The brightness of the display screen decreases as the brightness setting value decreases.

[0058] The brightness control unit 118 may save the brightness setting value at that time in the storage 23 when the host system 110 stops operating, that is, when the system state changes from the normal mode to the power-off. Then, when the host system 110 resumes operation, the brightness control unit 118 may read out the brightness setting value saved in the storage 23. The brightness control unit 118 may apply the read brightness setting value as the brightness setting value at that time and notify the display 14. Thereby, the display 14 can be used at the brightness indicated by the brightness setting value before the operation stop. Also, each time the power control mode notified from the setting processing unit 112 is changed, the brightness control unit 118 may update the brightness setting value to the reference value corresponding to the set of the power control mode and the power supply type.

[0059] Note that when the host system 110 stops operating, the luminance control unit 118 may save the luminance setting value in the storage 23 in association with the set of the power control mode and the power source type at that time. Each time one or both of the power control mode and the luminance setting value are changed, the luminance control unit 118 may read out from the storage 23 the luminance setting value corresponding to the set of the changed power control mode and luminance setting value. Thereby, the display 14 can be used at the brightness indicated by the luminance setting value corresponding to the set of the power control mode and the luminance setting value.

[0060] Next, an example of luminance control according to the present embodiment will be described. FIG. 7 is a flowchart showing an example of luminance control according to the present embodiment. However, FIG. 7 shows the process until a luminance setting value stored in advance is read out and the luminance setting value decreases to a reference value (default value) due to a change to the battery 34 of the power source type, or until an increase in the luminance setting value is instructed by a user operation. The user operation is an intention indication by the user, and automatic setting contrary to the intention indication is avoided.

[0061] (Step S102) The luminance control unit 118 reads out the luminance setting value last saved in the storage 23 in advance and sets the read luminance setting value to the display 14. In reading the luminance setting value, the luminance control unit 118 calls, for example, driver software and communicates with the OS. (Step S104) The usage detection unit 116 monitors the usage status (user scenario) of the information processing apparatus 1. When the system state is the S0 state, the usage detection unit 116 proceeds to the process of step S106.

[0062] (Step S106) The brightness control unit 118 determines whether the brightness setting value set at that time is greater than the reference value and whether the power supply type is changed from an external power supply to the battery 34 (AC / DC switching). The brightness control unit 118 refers to the brightness setting table and identifies the reference value (default value) of the brightness setting value corresponding to the power supply type and the power control mode set at that time. If it is determined that the brightness setting value is greater than the reference value and the power supply type is changed to the battery 34 (Step S106 YES), the process proceeds to the process of Step S108. If it is determined that the brightness setting value is less than or equal to the reference value or the power supply type is not changed to the battery 34 (Step S106 NO), the process returns to the process of Step S104. (Step S108) The brightness control unit 118 decreases the brightness setting value at that time by a predetermined change amount.

[0063] (Step S110) The brightness control unit 118 monitors whether an increase in the brightness setting value is instructed by a predetermined user operation. When an increase in the brightness setting value is instructed (Step S110 YES), the brightness control unit 118 increases the brightness setting value by a predetermined increase amount and sets the increased brightness setting value to the display 14. Then, the process of FIG. 7 ends. However, when the brightness setting value reaches the maximum value LMAX, the brightness setting value is not changed. Then, the process may proceed to the process of Step S104. When an increase in the brightness setting value is not instructed (Step S110 NO), the process proceeds to the process of Step S112. (Step S112) The brightness control unit 118 determines whether the brightness setting value has reached a predetermined reference value (default value). If it is determined that it has reached (Step S112 YES), the process of FIG. 7 ends. If it is determined that it has not reached (Step S112 NO), the brightness control unit 118 decreases the brightness setting value by a predetermined change amount and sets the decreased brightness setting value to the display 14. Then, the process returns to the process of Step S104.

[0064] <Second Embodiment> Next, the second embodiment of the present application will be mainly described with differences from the first embodiment. Matters not particularly specified are the same as those in the first embodiment, and the description thereof is incorporated herein by reference. The brightness control unit 118 according to this embodiment also monitors the power source type notified from the usage status detection unit 116. When the power source type is changed from an external power source to the battery 34 and the brightness setting value at that time is greater than the reference value of the brightness setting value when the power source type is the battery 34, the brightness setting value at that time is decreased by a predetermined change amount (decrease amount).

[0065] The brightness control unit 118 according to this embodiment decreases the brightness setting value due to the change of the power source type to the battery 34, and then increases the brightness setting value at that time when the power source type is changed from the battery 34 to an external power source. In this way, when the brightness setting value is smaller than the reference value when the power source type is an external power source, when the power source type is switched from the battery 34 to an external power source, the process of increasing the brightness setting value to a value between the current brightness setting value and the reference value when the power source type is an external power source may be referred to as "brightness increase process". However, the increase amount of the brightness setting value due to the change of the power source type to an external power source may be equal to the decrease amount of the brightness setting value due to the change of the power source type to the battery 34, or may be less.

[0066] For example, when the decrease amount of the brightness setting value when the power source type is changed to the battery 34 is a fixed value, the brightness control unit 118 may set the increase amount of the brightness setting value when the power source type is changed to an external power source to be less than the absolute value of the decrease amount of the brightness setting value. When decreasing the decrease amount of the brightness setting value due to the change of the power source type to the battery 34 as the brightness setting value is smaller, the brightness control unit 118 may decrease the increase amount of the brightness setting value due to the change of the power source type to an external power source as the brightness setting value is smaller.

[0067] When determining the amount of decrease in the brightness setting value due to the change to the battery 34 of the power supply type based on a certain decrease rate of the brightness setting value at that time, the brightness control unit 118 determines the amount of increase in the brightness setting value due to the change to the external power supply of the power supply type based on a certain increase rate of the brightness setting value at that time. However, the increase rate of the brightness setting value is set to a value smaller than the decrease rate of the brightness setting value. For example, when the decrease rate of the brightness setting value is 10 - 15%, the increase rate of the brightness setting value may be set to 5 - 8%.

[0068] Next, an example of the transition of the brightness setting value due to a change in the usage situation will be described with reference to FIG. 8. However, the increase in the brightness setting value by key operation and the decrease in the brightness setting value by AC / DC switching are the same as in the example of FIG. 8. Under this situation, assume that the user attaches the AC adapter 48 to the insertion port 48o of the information processing apparatus 1 (c. DC / AC switching). At this time, the attachment of the AC adapter 48 is detected in the EC 31, and a change in the power supply type from the battery 34 to the external power supply is detected. After the brightness control unit 118 decreases the brightness setting value due to the change to the external power supply of the power supply type, when a change from the external power supply of the power supply type to the battery 34 is detected, the brightness control unit 118 increases the brightness setting value at an increase rate smaller than the decrease rate used for the decrease. The brightness control unit 118 sets the increased brightness setting value to the display 14.

[0069] An example of the brightness control according to this embodiment will be described. FIG. 9 is a flowchart showing an example of the brightness control according to this embodiment. The processing in FIG. 9 includes the processing of steps S102 to S112 and the processing of steps S206 and S208. Since the processing of steps S102 to S112 is the same as the processing of steps S102 to S112 in the processing of FIG. 7, the description thereof is incorporated by reference. However, in step S106, when it is determined that the brightness setting value is less than or equal to the reference value, or the power supply type is not changed to the battery 34 (step S106 NO), the process proceeds to the processing of step S206.

[0070] (Step S206) The brightness control unit 118 determines whether the brightness setting value set at that time is obtained by decreasing due to the change from the external power supply of the power supply type to the battery 34 (AC / DC switching), and whether the power supply type is changed from the battery 34 to the external power supply (DC / AC switching). If it is determined that the brightness setting value has decreased due to the change from the external power supply of the power supply type to the battery 34 and the power supply type is determined to be changed to the battery 34 (Step S206 YES), the process proceeds to the process of Step S208. If it is determined that the brightness setting value has not decreased due to the change from the external power supply of the power supply type to the battery 34, or if it is determined that the power supply type is not changed to the external power supply (Step S206 NO), the process proceeds to the process of Step S104. (Step S208) The brightness control unit 118 increases the brightness setting value at that time by an increase amount smaller than the decrease amount related to the decrease in the brightness setting value. Then, the process proceeds to the process of Step S110.

[0071] <Third Embodiment> Next, the differences between the third embodiment of the present application and the first embodiment will be mainly described. Matters not particularly specified are common to the first embodiment, and the description thereof is incorporated herein. However, the differences described below may also be applied to the second embodiment.

[0072] When the usage status of the information processing apparatus 1 is changed, the brightness control unit 118 adds the brightness setting value to the changed usage status and stores it in the storage 23. The stored usage status information is formed as a setting history. The setting history may include information on the brightness setting value after the operation in association with an operation (for example, a key operation) for instructing an increase in brightness.

[0073] The luminance control unit 118 derives the probability that a predetermined operation is performed for each luminance setting value using the setting history. The derived probability tends to be higher as the luminance setting value is smaller and lower as the luminance setting value is larger. The luminance control unit 118 may determine, as the reference value (default value) of the luminance setting value, the luminance setting value at which the probability becomes equal to or less than a predetermined probability threshold (for example, 10 to 30%) using a predetermined mathematical model. The probability threshold may be set to a value closer to 0% than 100%. As the mathematical model, for example, probability distribution functions such as an error function and a sigmoid function can be applied. These probability distribution functions give, as the output value, the probability that asymptotically approaches the maximum value 1 as the input value increases and the probability that asymptotically approaches the minimum value 0 as the input value decreases. Here, the luminance control unit 118 performs regression analysis based on the probability derived for each luminance setting value, and determines a probability distribution function capable of calculating the probability for any luminance setting value within a predetermined value range. The luminance control unit 118 can search for, as the reference value, the luminance setting value that gives a predetermined probability threshold using the obtained probability distribution function.

[0074] Next, the setting of the reference value based on the operation will be described with reference to FIG. 10. However, the increase in the luminance setting value by the key operation and the decrease in the luminance setting value by the AC / DC switching are the same as in the example of FIG. 8. Assume that the initial luminance setting value is LD. Each time the luminance control unit 118 detects a predetermined key operation, it increases the luminance setting value by a predetermined increase amount (a. key operation). When the power supply type is changed from an external power supply to the battery 34 and the luminance setting value at that time is larger than the reference value of the luminance setting value when the power supply type is the battery 34, the luminance control unit 118 decreases the luminance setting value at that time (b. AC / DC switching). Each time the luminance setting value changes with the change in the usage situation in this way, the luminance control unit 118 records the luminance setting value in the setting history in association with the usage situation.

[0075] Among the individual information included in the setting history, the post-setting brightness setting value may or may not be associated with a predetermined key operation. The brightness control unit 118 refers to the setting history, tabulates the appearance frequency and the frequency associated with the key operation for each brightness setting value, and calculates the ratio of the latter to the former as the probability of the key operation being performed. The brightness control unit 118 determines, as a reference value in the case where the power source type is the battery, the brightness setting value at which the probability calculated based on a predetermined mathematical model becomes a predetermined probability threshold (d. learning the reference value of the brightness setting value based on the key operation). This brightness setting value can be regarded as a value at which the brightness of the display screen is sufficient and thus an increase in brightness by a key operation is not required. The brightness control unit 118 sets the brightness setting value LD’ obtained based on the setting history as its reference value (e. adjusting the brightness setting value based on the learned reference value). The brightness control unit 118 uses the set reference value as the minimum value of the brightness setting value when the power source type is the battery 34. When the power source type is changed from an external power source to the battery 34 and the brightness setting value at that time is greater than the newly set reference value, the brightness control unit 118 decreases the brightness setting value at that time. Therefore, when the brightness setting value at that time becomes less than or equal to the newly set reference value, even if the power source type is changed from an external power source to the battery 34, the brightness control unit 118 does not decrease that brightness setting value.

[0076] Note that the brightness control unit 118 may determine the reference value of the brightness setting value for each power control mode by referring to the setting history. This is because the desired brightness of the display screen may vary for each power control mode. The brightness control unit 118 may update the reference value determined for a certain power control mode with the reference value corresponding to the set of that power control mode and the battery as the power source type in the brightness setting table. The brightness control unit 118 may wait for an operation signal indicating the power control mode from the input device 32. The brightness control unit 118 refers to the brightness setting table and identifies the reference value corresponding to the set of the power control mode indicated by the input operation signal and the power source type at that time. The brightness control unit 118 sets the identified reference value to the display 14.

[0077] As described above, the information processing apparatus 1 according to the present embodiment includes a power supply circuit 33 to which power is supplied from a power source, and a brightness control unit 118 that controls the brightness of the display 14. The brightness control unit 118 includes a first reference value when the power source type is an external power source, and a second reference value that is smaller than the first reference value and is used when the power source type is the battery 34, as reference values for the brightness setting value that is the set value of the brightness. The brightness control unit 118 sets the brightness setting value to a user setting value specified by the user in response to an operation by the user. When the power source type switches from an external power source to the battery 34 while the user setting value is greater than the second reference value, the brightness control unit 118 executes a brightness reduction process of reducing the brightness setting value to a value between the user setting value and the second reference value. When the power source type switches from the battery 34 to an external power source while the brightness setting value is smaller than the first reference value, the brightness control unit 118 executes a brightness increase process of increasing the previous setting value to a value between the current brightness setting value and the first reference value.

[0078] According to this configuration, the user setting value increased in response to an operation decreases when the power source type switches to the battery 34. Since the brightness of the display 14 decreases even when an operation mainly for reducing the brightness is not performed, the power consumption of the entire information processing apparatus 1 is reduced. The decreased user setting value increases when the power source type switches to an external power source. In this case, an increase in power consumption due to the supply of power from the external power source is allowed, and the visibility can be improved by increasing the brightness of the display 14.

[0079] Also, when the power source type switches from the battery 34 to an external power source, the brightness setting value may be increased in the brightness increase process by an amount of change smaller than the amount of change related to the decrease in the brightness setting value in the brightness reduction process. According to this configuration, the brightness is restored to a brightness lower than the brightness before the brightness decrease. Therefore, it is possible to reduce the impression on the user due to an excessive increase in brightness.

[0080] The luminance control unit 118 may update the second reference value based on the frequency of operations performed by the user for each luminance setting value. According to this configuration, the reference value in the case where the power source type is the battery 34 is updated based on the frequency distribution of operations performed by the user for each luminance setting value. By adopting, as the reference value, a luminance setting value with a low frequency of operations performed by the user, it is possible to improve the satisfaction with respect to the luminance based on the reference value.

[0081] The second reference value is larger for a power control mode with a larger rated power of the host system 110. The second reference value is larger for a power control mode with a larger rated power of the host system 110. The luminance control unit 118 may set the luminance setting value to a reference value corresponding to a set of the selected power control mode and the power source type. Therefore, it is possible to improve the satisfaction with respect to the luminance corresponding to the power control mode selected by the operation.

[0082] Note that design matters such as various setting information and parameters related to the above processing are not limited to those illustrated, and may differ according to various requirements such as the capabilities of the host system 110 and the display 14. For example, the number of steps of the power control mode is not limited to three steps, and may be two steps or four steps or more.

[0083] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the above-described embodiments, and designs and the like within the scope not departing from the gist of the present invention are also included. Each configuration described in the above embodiments can be arbitrarily combined.

Description of Reference Numerals

[0084] 1... Information processing device, 11... Processor, 12... Main memory, 13... Video subsystem, 14... Display, 21... Chipset, 22... BIOS memory, 23... Storage, 24... Audio system, 25... WLAN card, 26... USB connector, 31... EC, 32... Input device, 33... Power circuit, 34... Battery, 36... Power button, 32k... Keyboard, 32t... Touchpad, 42... Lid sensor, 44... Acceleration sensor, 48... AC adapter, 48o... Plug-in port

Claims

1. A power supply circuit supplied with power from a power source, and a brightness control unit that controls the brightness of a display, wherein the brightness control unit, as a reference value of a brightness setting value that is a set value of the brightness, includes a first reference value when the power source type is an external power source and a second reference value that is smaller than the first reference value and is for the case where the power source type is a battery, sets the brightness setting value to a user setting value specified by the user according to an operation by the user, when the power source type switches from an external power source to a battery in a state where the user setting value is greater than the second reference value, executes a brightness reduction process of reducing the brightness setting value to a value between the user setting value and the second reference value, when the power source type switches from a battery to an external power source in a state where the brightness setting value is smaller than the first reference value, executes a brightness increase process of increasing the brightness setting value to a value between the current brightness setting value and the first reference value An information processing apparatus.

2. wherein the brightness control unit, when the power source type switches from a battery to an external power source, increases the brightness setting value in the brightness increase process by a change amount smaller than a change amount related to the decrease in the brightness setting value in the brightness reduction process The information processing apparatus according to claim 1.

3. wherein the brightness control unit, updates the second reference value based on the frequency of operation by the user for each brightness setting value The information processing apparatus according to claim 1.

4. The second reference value is larger as the power control mode with a larger rated power of the host system is, wherein the brightness control unit, sets the brightness setting value to a reference value corresponding to a set of the selected power control mode and the power source type The information processing apparatus according to claim 1.

5. A control method for an information processing apparatus including a power supply circuit supplied with power from a power source and a brightness control unit that controls the brightness of a display, wherein the information processing apparatus, as a reference value of a brightness setting value that is a set value of the brightness, includes a first reference value when the power source type is an external power source and a second reference value that is smaller than the first reference value and is for the case where the power source type is a battery, and a step of setting the brightness setting value to a user setting value specified by the user according to an operation by the user ​ When the power supply type switches from an external power supply to a battery in a state where the user setting value is greater than the second reference value, a brightness reduction process is executed to reduce the brightness setting value to a value between the user setting value and the second reference value. When the power supply type switches from a battery to an external power supply in a state where the brightness setting value is less than the first reference value, a brightness increase process is executed to increase the brightness setting value to a value between the current brightness setting value and the first reference value. Control method.

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