JPH11326866A - Information processing apparatus, backlight brightness / contrast control method, and storage medium - Google Patents

Abstract

(57) [Problem] To appropriately perform volume control on any of a plurality of liquid crystal display panels having different volume control characteristics of backlight luminance and contrast. SOLUTION: A control parameter for controlling a backlight luminance and a contrast corresponding to various LCD panels is stored, and a type of the LCD panel is detected, thereby controlling the LCD panel corresponding to the detected type. Based on the parameters, the backlight brightness and the default value for volume control of the contrast are automatically set, and when an instruction to change the backlight brightness and the contrast is issued, the LCD panel corresponding to the detected type is changed. With reference to the control parameters, a process of changing the backlight luminance and contrast according to the change instruction is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for controlling the brightness and contrast of a backlight of a liquid crystal display panel mounted on an information processing apparatus.

[0002]

2. Description of the Related Art Generally, in a notebook personal computer (hereinafter referred to as a notebook PC), an LCD (Literature Computer) is used.
The backlight brightness and contrast of a liquid crystal display (quid Crystal Display) panel can be finely adjusted by pressing a key on a built-in keyboard.

FIG. 17 shows an example of such a backlight luminance and contrast adjustment mechanism. In the example of FIG. 17, the power supply is turned on (system DC / D
KBC (K) operating only in C converter 1601
Eye Board Controller) 1602, the built-in keyboard 1603 is scanned to detect a pressed key, and based on the detection result, the LCD panel 1
External D / A converters 1604 and 16 for varying the backlight brightness and contrast volume
05 is controlled by an up / down signal. At this time, D
The reference voltage of the / A converters 1604 and 1605 is
A voltage (Vref) that matches the characteristics of the LCD panel used
1, Vref2) is generated from the system voltage (Vsys) and input. In addition, electrically erasable EEPR
It is also known that the OM is built in the D / A converters 1604 and 1605 so that once the user makes the adjustment, it is not necessary to readjust it at the next power-on.

In order to further reduce the size and weight of a notebook PC, as shown in FIG.
17 using a KBC 1701 with a built-in 4 and 1705.
In the example above, the PMC used mainly for power management
(Power Management Control
ler) 1607 has been developed into the KBC 1701. In this example, KBC17
Since the backlight brightness and contrast volume values in 01 are maintained at a power supply (Vpmc) different from the system power supply even when the system DC / DC converter 1601 is not oscillating, there is no need for an EEPROM and cost. Is also advantageous.

[0005]

However, the example of FIG. 18 has the advantage that it can be reduced in size, weight and cost, but has its disadvantages.

That is, when different types of LCD panels are mounted, in the example of FIG. 17, as a measure against the difference in the characteristics of the LCD panels, a reference voltage input to an external D / A converter is used. Once you change it,
The KBC requires only up / down control of an external D / A converter without considering the characteristic difference of the LCD panel, and a common ROM is used for various LCD panels.
Can also be used.

On the other hand, in the example of FIG.
In order to perform A-conversion output, it is necessary to perform control appropriate for the characteristics of the LCD panel by using the KBC.

Taking the contrast as an example, as shown in FIG. 19, an 11.3-inch DSTN (Dualsc) of Company T
an Super Twisted Nematic)
In the case of a panel, the effective visible region of the contrast is set to a drive voltage in the range of 1.53 V to 1.92 V. At room temperature, 1.70 V is the optimum value.
In the 12.1-inch DSTN panel of Company T, the effective visible region of the contrast is a drive voltage of 1.24 V to 1.8.
The effective range of 2V is considered to be 1.49V at room temperature, and the optimum value of the 12.1 inch DSTN panel of Company P is that the effective visible region of the contrast is 0V to 1.88 in drive voltage.
The range of V is considered to be effective, and the optimum value is 0.53 V at room temperature. Since the contrast requires fine adjustment, generally 32 levels to 64 levels are required, and controlling in 64 steps within the range of the effective visible region described above is the optimum contrast for these LCD panels. Volume control.

As described above, the characteristics of the LCD panel differ depending on the model, even if the manufacturer or the same manufacturer. Therefore, in the example of FIG.
Inch DSTN (Dualscan Super Tw)
If you are producing 12.1 inch type notebook PCs with an installed nematic) panel and want to switch to a cheaper 12.1 inch DSTN panel of Company P, the effective visible areas of both are as follows: 1.24
Since V is very different from 1.82V and 0V to 1.88V, and the optimum value at room temperature is also very different, such as 1.49V and 0.53V, the contrast volume control needs to be reviewed, that is, the ROM for KBC needs to be changed. This becomes an obstacle to timely switching of the LCD panel.

For example, for example, a company 12.1 inch DST
Even if two types of models of N and T company 11.3 inch DSTN are assumed in advance, there are some problems.

Since these two LCD panels have relatively similar characteristics, a common contrast volume control can be applied. More specifically, as shown in FIG. 19, the lower limit is set to 1.24 V for a 12.1-inch panel, and the upper limit is set to 1.92 V for a 11.3-inch panel. If the contrast volume control for taking 1.6 V is performed, both panels can be supported to some extent.

However, even in this case, the following two problems remain. First, there is the problem of initial values. In each panel, the difference between the above initial value (1.6 V) and the optimum value is about 0.1 V. However, from the user's point of view, it is slightly dark or slightly too bright, requiring fine adjustment. Would.

Second, there is a problem of the adjustment amount per one stage. As shown in FIG. 19, the optimum contrast control for the 11.3 inch DSTN panel of Company T is to adjust from 1.53V to 1.92V in 64 steps, but as described above, from 1.24V to 1.92V. If the 92V is adjusted in 64 steps, the amount of change per level becomes too large compared to the optimal control, leaving a problem that the ideal fine adjustment cannot be performed sufficiently.

The present invention has been made under such a background, and an object of the present invention is to appropriately control the volume of any of a plurality of liquid crystal display panels having different backlight luminance and contrast volume control characteristics. To be able to do it.

[0015]

In order to solve the above-mentioned problems, the present invention relates to an information processing apparatus having a liquid crystal display panel, comprising: detecting means for detecting the type of the liquid crystal display panel; Storage means for storing control parameters for controlling the backlight brightness / contrast for each type, and corresponding to the type of the liquid crystal display panel detected by the detection means from at least the control parameters stored in the storage means And control means for controlling the backlight brightness and contrast of the liquid crystal display panel based on the control parameters selected by the selection means.

According to the present invention, in an information processing apparatus having a liquid crystal display panel, a detecting step of detecting a type of the liquid crystal display panel, and controlling at least a backlight luminance and a contrast for each type of the liquid crystal display panel. A storage step of storing control parameters for, a selection step of selecting a control parameter corresponding to a type of the liquid crystal display panel detected by the detection step from at least the control parameters stored by the storage step, Controlling the backlight brightness / contrast of the liquid crystal display panel based on the control parameter selected in the selecting step.

Further, the present invention is a storage medium storing a program for controlling a backlight luminance / contrast of a liquid crystal display panel mounted on an information processing apparatus, wherein the program is a type of the liquid crystal display panel. And a storage routine for storing at least a control parameter for controlling backlight brightness / contrast for each type of the liquid crystal display panel, and a storage routine for storing at least the control parameter from among the control parameters stored by the storage routine. A selection routine for selecting a control parameter corresponding to the type of the liquid crystal display panel detected by the detection routine, and a control routine for controlling the backlight brightness / contrast of the liquid crystal display panel based on the control parameter selected by the selection routine And

In the present invention, the storage means / step /
The routine stores, as the control parameters for each type of the liquid crystal display panel, an initial level together with a plurality of control parameters for each control level, and the selecting means / step / routine is stored in the storage means / step / routine. The control parameters and the initial level, select a control parameter and an initial level corresponding to the type of the liquid crystal display panel detected by the detection unit / step / routine detected by the detection unit, and the control unit / step / routine includes: The control parameters corresponding to the initial level among the control parameters selected by the selection means / step / routine are initialized.

Further, in the present invention, the selecting means, the step,
The routine selects a control parameter and an initial level corresponding to a predetermined liquid crystal display panel when the power is turned on. The control means / step / routine selects a control parameter corresponding to the initial level among the control parameters selected at the time of power supply. Is set as a default value, and the detection means, process,
If the liquid crystal display panel detected by the routine is different from the predetermined liquid crystal display panel,
As a control parameter corresponding to the type of the liquid crystal display panel detected by the routine, the control parameter corresponding to the initial level among the control parameters selected by the selection means, the process, and the routine is set again as a default value.

Further, according to the present invention, the detecting means, the process,
After the execution / non-execution of the control parameter resetting process based on the detection result by the routine is completed, a power-on control means / process / routine for turning on the power to the backlight is provided.

In the present invention, the control means / step /
The routine changes the default value within a range of the control parameter selected by the selecting means / step / routine in response to an operation of a predetermined operating means.

Further, according to the present invention, the control means, the step,
There is provided a level storage means, a process, and a routine for holding the current level of the control parameter set by the routine even when the information processing apparatus is not powered on.

In the present invention, the storage means / step /
Routines, selection means / processes / routines, control means / processes / routines, power-on control means / processes / routines, and level storage means / processes / routines are built in the keyboard controller or executed by the keyboard controller.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a perspective view showing an outer shape of a portable notebook personal computer (hereinafter, referred to as a notebook PC) as an information processing apparatus according to an embodiment of the present invention. This notebook PC is
As shown in FIG. 2, an apparatus main body (hereinafter, referred to as a PC main body) that can be driven by DC power supplied from the battery pack 2
The battery pack 2 is detachably mounted on the PC main body 1, and a built-in keyboard 3, LE
D4, power switch 5, LCD (Liquid Cr)
An AC adapter insertion opening (not shown) is provided on the rear display panel 11 and on the back of the main body. The brightness level and contrast level of the backlight of the LCD panel 11 can be adjusted by the user with a combination of the Fn key on the built-in keyboard 3 and each of the function keys F5 to F8. Specifically, the brightness can be increased with the Fn key and the F5 key, the brightness can be reduced with the Fn key and the F6 key, the contrast can be increased with the Fn key and the F7 key, and the contrast can be reduced with the Fn key and the F8 key.

Next, the internal configuration of the notebook PC will be described with reference to FIG. FIG. 1 shows the notebook PC of FIG.
FIG. 2 is a block diagram showing an internal configuration of the device. Notebook PC
As shown in FIG. 1, an LCD unit U, an MPU board B1 mainly including an MPU, a memory board B2 including a memory-related chip, a power supply board B3 including a power-related chip, and various IO-related chips are included. It has an IO board B4 mounted and a switch board B5 mounted with switches and LEDs.

The LCD unit U has a backlight 1 for improving visibility in addition to the LCD panel 11 described above.
2. Inverter 13 for controlling backlight 12, and VGA (Video Gra) on I / O board B4.
A video-related signal group output from the Physs Array controller 54 is converted to a TFT (Thin FilmT).
ransister) type and DSTN (Dualscan)
An LCD board 14 for conversion so as to be compatible with various types of LCD panels 11 such as a Super Twisted Nematic type is mounted.

The LCD panel 11 includes an LCD panel 11
A pattern for mounting three resistive elements for setting the panel ID is prepared, and a panel ID from 0 to 7 can be set by mounting / non-mounting the resistive elements. In this embodiment, the S company 12.1 inch FT is
D1 defines the T company's 11.3 inch DSTN as 1D3, T company's 12.1 inch DSTN as ID4, and P company's 12.1 inch DSTN as ID6. Even when the LCD panel 11 is switched to another type by the LCD board 14 with the ID, a common backlight 12 and inverter 13 can be used.

The three signal lines 59 indicating the panel ID are
PCI-ISA bridge chip 51 on I / O board B4
Is connected to an input port of a GPIO (general-purpose input / output port), and is stored in the BIOS ROM 55.
(Basic Input Output System
m) is a POST (Power On Self) described later.
During the (Test) process, the type of the LCD panel 11 incorporated can be recognized by I / O reading the panel ID via the corresponding GPIO of the PCI-ISA bridge chip 51. The opening / closing signal of the LCD panel 11 from the lid switch 6 on the switch board B5 is input to the port assigned for WAKEUP of the PCI-ISA bridge chip 51.

The backlight 1 of the LCD panel 11
Backlight ON / OFF control signal 6 for turning off 2
2 is a backlight 12 on the LCD unit U for reducing power consumption and heat generation when the LCD panel 11 is closed.
Is output to When the lid switch signal changes due to the opening and closing of the LCD panel 11, the BIOS:
SMI (System Management Int)
During the error (errupt) processing, the I / O read of a predetermined register of the PCI-ISA bridge chip 51 causes
The switch 6 is recognized as an SMI, and the ON / OFF of the backlight 12 is controlled by an I / O write of a predetermined register of the PCI-ISA bridge chip 51 as necessary.

The chip on the I / O board B4 is PCI (P
eripheral Computer Interc
connect) bus and the ISA
(Industrial Standard Arch
item) and those connected to the bus. In addition to the aforementioned PCI-ISA bridge chip 51, a PCI bus (PCMC)
nal Computer Memory Card)
Drive 52 that controls the hard disk, IDE (Integrated Drive) that controls the hard disk
(Electronics) controller 53 and a VGA (Video) for controlling display of the LCD panel 11.
o Graphics Array) Controller 54
Etc. are connected. The ISA bus stores a basic input / output control code (BIOS).
POST (Power On) described later even when there is no power supply such as the SROM 55, the AC adapter and the battery pack 2.
RTC (Real Time Clock) chip 56 for holding Self Test (Self Test) information and setup information, FDD, FIR (Fast Infrared)
Rays), a super I / O chip 57 for controlling a serial port, a parallel port, etc., and a built-in keyboard 3
And a keyboard controller 58 for performing power management.

In this embodiment, as the keyboard controller 58, a ROM, a RAM, an A / D converter, a D /
H8 / 3434F, which is an 8-bit one-chip microcomputer manufactured by Company H and has peripheral functions such as an A converter built in one chip, is used. Thus, in the following description, the keyboard controller 58 may be referred to as H8.

The keyboard controller 58 has an IS
In addition to the A bus, the keyboard is connected to a built-in keyboard 3, a pointing device 31, an input signal from the power switch 5 on the switch board B5, an output signal to the LED 4, a power circuit 71 on the power board B3, and the like. Power ON / OF in addition to control (KBC) function
It also supports a so-called power control (PMC) function such as F control and detection of the charge / remaining amount of the battery pack 2 via the power supply circuit 71. Further, the keyboard controller 58
The output signals of the two-channel D / A converter 58a incorporated in the LCD controller 14 are connected to the inverter 12 and the LCD panel 11 on the LCD board 14 as a backlight brightness control signal 60 and a contrast control signal 61, respectively. In accordance with the D / A output voltage value from 58, the backlight brightness and contrast of LCD panel 11 change. That is, the keyboard controller 58 also supports the volume control function of the LCD panel 11.

As shown in FIG. 1, among the electronic components on the I / O board B4, only the keyboard controller 58 is supplied with power from the keyboard DC / DC converter 72, and the other electronic components are controlled by the keyboard controller 58. ON / OFF controlled system DC / DC converter 73
Power is supplied from.

FIG. 3 is a block diagram mainly showing the keyboard controller 58. First, functions regarding the keyboard will be described. Functions related to the keyboard include 16 Scan Out signals and 8 Return
A key scan function (8051 compatible function) for detecting a key pressed by the user based on the n signal, a key code corresponding to the key pressed by the user of the built-in keyboard 3, or a full keyboard or mouse connected to the outside. A function (8052 compatible function) for notifying the BIOS of a key code or information to be transmitted to the BIOS. Communication between the BIOS and the keyboard controller 58 includes a chip select signal (KBCS1 * / KBCS2 *) for the KBC and I / O of the ISA bus.
Read / write signals (IOR * • IOW *) and I
Eight data buses from D0 to D7 of SA bus, keyboard interrupt (IRQ1) and mouse interrupt (1RQ1)
The signal of 2) is further realized by a signal group such as an H8SMI signal used as a trigger signal for notifying the BIOS that the battery pack 2 or the AC adapter 101 has been inserted or removed or the remaining amount of the battery pack 2 has become low. .

Next, functions related to the power supply will be described. The power supply to the keyboard controller 58 is performed by the keyboard DC / DC converter 72. When the battery pack 2 or the AC adapter 101 is inserted, the keyboard DC / DC converter 72 unconditionally supplies power to the keyboard controller 58 by the one-shot circuit 78 for a certain period of time (5 Omsec). The power supply to the keyboard controller 58 is switched according to the HOLDH8 signal output from the 58. The connection / disconnection of the AC power supply is detected by the EXACEN signal. When the AC power supply is connected, the AC FET 75 is controlled by the ACDCEN signal to connect the AC power supply to the power line. The connection / disconnection of the battery pack 2 is based on BATTM for detecting the temperature inside the battery pack 2.
This is performed based on the A / D conversion value of the P signal. According to the connection / disconnection of the battery pack 2 and the connection / disconnection of the AC power supply, the FE is generated by the BATEN1 and BATEN2 signals.
By controlling T76 and T77, the connection between the battery pack 2 and the power line is controlled. Between the battery pack 2 and the keyboard controller 58, BATCLK and BATD
The AT is connected by two 12C buses, and the keyboard controller 58 is connected to the System Managerme.
Various battery statuses held by the microcomputer in the battery pack 2 can be obtained by a command protocol based on nt Bus (hereinafter referred to as SMB).

The depressed state of the power switch 5 constituted by a toggle switch is inputted as a PWRSW signal. When a continuous depressed state for a predetermined time or more is detected, the system DC / DC converter 7 is activated by a DCON signal.
3 to start the power supply from the AC adapter 101 or the battery pack 2 to the system side.
After a lapse of a fixed time from the start of oscillation of the system DC / DC converter 73, the reset signal on the system side is released by the reset IC 74, and the POST process of the personal computer is started. That is, the keyboard controller 58 always operates as long as either the battery pack 2 or the AC adapter 101 is connected, even if the personal computer body is in the power-off state.
The contents of the internal RAM 8 are also held.

Next, the volume control functions of backlight luminance and contrast will be described. The keyboard controller 58 includes two channels of 8-bit D / A converters 58a, and can output any voltage from OV to 5V based on 5V which is an analog reference voltage. As described above, the output signals of the two-channel D / A converter 58a are output to the LCD unit U as the backlight luminance control signal 60 and the contrast control signal 61.

As described above, the keyboard controller 5
8 has a function of controlling the system DC / DC converter 73, detecting the presence or absence of the connection of the AC adapter 101, and further scanning the built-in keyboard 3; Backlight brightness control signal 60
By changing the output voltage level of the contrast control signal 61, the backlight luminance and contrast of the LCD panel 11 are changed.

The BIO of the notebook PC thus configured
S and the control flow executed by the keyboard controller 58 will be described with reference to FIG.

[POST Processing by B1OS] In a state where power is not supplied to the system power supply line (power-off state), the keyboard controller 58 detects that the power switch 5 is pressed, and the system DC is controlled by a DC / DC control signal. When the / DC converter 73 starts oscillating, B
The POST process executed by the IOS will be described with reference to FIG.

First, in step S1, a POST process (Power On) of hardware that cannot be removed is performed.
Self Test). Specifically, initialization of various registers in the memory controller 32 and checking of the on-board memory are performed.
The initialization of each chip such as the PCI-ISA bridge chip 51, the PCMC controller 52, and the IDE controller 53, and the super I / O 57 on the ISA bus is performed.

In the next step S2, the LCD board 14
, The panel ID of the LCD panel 11 input to the GPIO pin of the PCI-ISA bridge chip 51 is obtained. In step S3, a process of setting various registers in the VGA controller 54 is executed via the PCI bus based on the obtained panel ID.

Subsequently, initialization of each controller on the ISA bus is performed. That is, first, in step S4
Then, the keyboard reset command (FFh) is I / O-written to 60h, and waits until AAh indicating that the keyboard controller 58 has completed the reset processing is returned to the I / O address 60h.

Next, in step S5, the panel ID of the LCD panel 11 is notified to the keyboard controller 58 via the ISA bus. Specifically, the panel ID notification command (4B) is I / O-written to 66h, and then the panel ID number (n) is I / O-written to 62h. The panel ID number (n) is used for controlling the volume of the LCD panel 11 by the keyboard controller 58 described later.

In step S6, the configuration information backed up in the memory in the RTC 56 is obtained. This configuration information includes I / O addresses and modes of parallel ports and serial ports,
It includes system configuration information such as FDD and HDD types and connection information, memory size, and power management setting information for these I / O groups. In step S7, based on the configuration information, the devices (HDD, FDD,
F1R, serial port, parallel port, keyboard, etc.).

In step S8, the power supply to the backlight 12 is started using the backlight on / off signal via the PCI-ISA bridge chip 51. As a result, the LCD panel 11 becomes visible.

Next, in step S9, the size and read / write check are performed on the expanded memory other than the on-board memory. Finally, at step S10, the POS
It is determined whether or not the T process has succeeded. If an error occurs during the processing from step S1 to step S9 (for example, when the configuration information obtained from the memory in step S6 is inconsistent with the result detected in the actual POST processing), the POST processing is performed. Is determined to have failed, the process proceeds to step S11, a setup menu is displayed on the LCD panel 11, the user is prompted to reset, and the process from step S1 is repeated again. If there is no error, it is determined that the POST process has succeeded, the process proceeds to step S12, the POST process by the BIOS ends, and control is passed to the POST process by the OS.

As will be described later with the control by the keyboard controller 58, the keyboard controller 58 controls the contrast of the LCD panel 11 and the volume control of the backlight brightness at the timing when the BIOS sets the panel ID to the keyboard controller 58 in step S5. The parameters concerning (the minimum voltage, the maximum voltage, the amount of change per level, the contents of a lookup table for determining the output voltage from the level, etc.) are reconstructed as necessary.
When reconstructed, the backlight brightness control signal 6
0 or the output voltage of the contrast control signal 61 changes. However, it is in step S8 that the LCD panel 11 becomes visible as described above, and the appearance of the LCD panel 11 during the display is irrespective of the user's intention.
Does not change.

Next, a control procedure of the keyboard controller 58 will be described with reference to FIG.

[Overall Control Flow of Keyboard Controller] FIG. 5 is an overall flowchart showing a control procedure of the keyboard controller 58 in the notebook PC of FIG.

First, the keyboard controller 58
An initialization routine for initializing the / O port, initializing the built-in RAM, setting interrupts, and initializing modules built into the keyboard controller 58 such as an A / D converter and a D / A converter is executed (step S1). S20). Subsequently, a PM (Power Management) control routine (step S21) for controlling the power supply state of the keyboard controller 58 itself and a main routine (step S22) for controlling execution / non-execution of each service routine described later are executed.

The main routine is executed at a period of 10 msec and performs I / O for monitoring various input / output signals.
Service routine (step S23), F for controlling various FETs based on the detection result of the I / O service routine
ET control service routine (step S24), 100
A battery control service routine (step S
25) is included. In the main routine, during power-on (when power is supplied from the system DC / DC converter 73 to the system), a so-called 8
Output of the brightness and contrast of the LCD panel 11 when the corresponding key is pressed based on the key scan result of the 8042 compatible keyboard service routine (step S26) having the 051 compatible function (internal keyboard scan function) and the keyboard service routine. An LCD panel volume control service routine for performing control (step S27) is also included.

Here, among the above control routines, an initialization routine, an FET control service routine, a keyboard service routine, and an L routine closely related to the present invention.
About CD panel volume control service routine
This will be described in detail.

[Initialization Routine] In the present embodiment, as described above, the keyboard controller 58
It is constituted by a so-called one-chip microcomputer manufactured by Company H with built-in AM, I / O, etc., and if power is supplied from either the AC adapter 101 or the battery pack 2, regardless of the operation of the system side, it is always It is working. An initialization routine executed only once after the reset of the keyboard controller 58 is released will be described with reference to FIG.

When the power is not turned on at all, AC
When the adapter 101 or the battery pack 2 is attached, power is unconditionally supplied from the keyboard DC / DC converter 72 to the keyboard controller 58. When the reset of the keyboard controller 58 is released after the start of the power supply, the stack pointer is initialized in the same manner as the general microcomputer initialization processing (step S3).
0) Then, initialization of the I / O register and the internal RAM, and further, initialization of the built-in module are executed (step S31).

In the above-mentioned initialization of the I / O register, regarding the input / output direction register, the ports of the power switch 5, the AC adapter 101 and the like are in the input direction, and various FET control signals including the DC / DC control signal are Set in the output direction. Of the I / O ports set in the output direction, HOL
The DH8 signal is unconditionally set to Hi and the keyboard DC / DC
The power supply from the converter 72 to the keyboard controller 58 is continued. FETs such as ACDCEN and BATEN
The control signal is set according to whether the AC adapter 101 or the battery pack 2 is attached. Also, a signal group connected to the ISA bus or a two-channel D / A converter 58a
Here, the signal group that functions only in the power-on state, such as the output signal, is set in the input direction to prevent a leak current, and is initialized again when the power supply to the system side is started. Will be.

Next, the internal work RAM of step S32
Of the work RAM related to the volume control of the LCD panel 11, which is closely related to the present invention, will be described.

Internal RAM of keyboard controller 58
The following work areas are secured for volume control of the LCD panel 11. First, TFT type, D
As a work area common to the STN type LCD panel, a work area (1 byte: Panel-ID) for holding the panel ID of the LCD panel 11 is secured. Regarding the contrast volume control for the DSTN panel, the contrast lookup table (64) is used.
Stage: 64 bytes: Contrast-TBL) and a work (1 byte: Contrast-Lvl) for holding the current level of contrast are secured. Further, regarding the volume control of the luminance of the backlight 12, a look-up table of the backlight luminance (8 stages: 8 bytes: Backlight-TB)
L) and a work area for holding the current level of the backlight 12 (1 byte: Backlight-
Lvl) is secured.

Table data corresponding to the following various LCD panels is prepared in the internal ROM 58b. That is, backlight table data (8 bytes) dedicated to the LCD panel corresponding to panel ID3,
LCD panel backlight table data (8 bytes) corresponding to other panel IDs, LCD panel contrast table data (64 bytes) corresponding to panel ID 4 and optimum level at room temperature, LCD panel corresponding to panel ID 5 The contrast table data (64 bytes) for LCD panel and the optimum level at room temperature, and the contrast table data for LCD panel corresponding to panel ID 6 (64 bytes) and the optimum level at room temperature are stored in the internal ROM 58.
b is preset. Note that the internal ROM 58b also stores programs corresponding to the flowcharts of FIGS.

In the initialization processing of the work RAM, the P company 1 corresponding to the panel ID 6 which is the model with the largest production volume
Data for 2.1 inch DSTN type LCD panel
The initial value of the keyboard controller 58 is set in each of the work areas described above. That is, Panel-I
D is set to "6" (step S33), and Cont
Last-TBL has 0 V which is the output voltage of level 0.
64 panel IDs 6 from “0” to “204” corresponding to 4V which is the output voltage of level 63.
The contrast table data for internal ROM 58b
(Step S34). Also, Contrast-Lvl holding the current level of contrast
, "31" corresponding to the output voltage of 2 V, which is the optimum value at room temperature, is set as a default value (step S).
35).

Similarly, with respect to the work relating to the backlight luminance, the Backlight-TBL includes 8 values from “0” corresponding to 0 V which is the output voltage of level 0 to “163” corresponding to 3 V which is the output voltage of level 7. The backlight table data for panel ID6
It is set from the OM 58b (step S36). Also,
Backl holding the current level of backlight brightness
In the light-Lvl, “3” corresponding to the output voltage of 1.5 V, which is the center value, is set as a default value (step S37).

Finally, initialization of various registers for analog-related built-in modules such as the A / D converter 58a and the D / A converter (step S38), and a 1 msec timer interrupt which is a reference timer of the keyboard controller 58 is executed. The timer register for generation is set (step S39).

A D / A converter 58a used for volume control of the LCD panel 11, which is particularly related to the present invention.
As for, there is a D / A data register and a D / A control register. D / A data register is D / A
The D / A control register is a register for setting data to be converted. The D / A control register is a register for controlling whether or not to output a D / A conversion result. In the power-off state, when the D / A conversion output is performed, a leak current occurs to the LCD panel 11 to which the power is not turned on. Therefore, the D / A control register is set to the output prohibited state.

[FET Control Service Routine] The FET control service routine is based on the connection information of the AC adapter 101 and the battery pack 2 and the monitoring information of the power switch 5 by the I / O service routine. System DC / D for controlling power supply to FETs 76 and 77 and system side
This is a routine for controlling the FET for C (built-in to the system DC / DC 73, not shown) and the like. Among them, the control of the FET for system DC / DC closely related to the present invention will be mainly described with reference to FIGS. I will do it.

Referring to the detection result of the pressing of the power switch 5 checked in the I / O service routine (step S40), if the pressing is not determined, the control of the system DC / DC converter 73 is skipped. And other FET
Branch to control. If the depression of the power switch 5 is determined, the output state of the system DC / DC converter 73 is checked (step S41). If not, that is, if the power switch 5 is off, that is, the system DC / DC converter 73 is off. Is pressed, the system DC / DC
The ON process of the converter 73 is executed (step S42).
After waiting 50 msec until the output from the system DC / DC converter 73 is stabilized (step SS43), the ISA
The I / O port connected to the system by the bus is initialized (step S44).

Next, initialization for the keyboard service is executed. First, in order to enable use of the host interface function built in the keyboard controller 58, related internal registers are initialized (step S45), and a work area used in the keyboard service is initialized (step S46). After permitting the interface interrupt (step S47), a key scan control timer in the keyboard service is started (step S47).
48).

Next, the set value of the D / A data register is determined. That is, the current contrast level (Contrast-Lvl) held in the internal RAM
, A 1-byte digital value (α) of the corresponding level is obtained from the contrast lookup table (Contrast-TBL) on the RAM (step S
49), and the digital value (α) is converted to the D / A
It is set in the data register (step S50). For example, in the case of the first power-on after the reset of the keyboard controller 58, "31" is set in Contrast-Lvl as described in the initialization routine. Therefore, the 1-byte value “102” located at the 31st byte from the top of the Contrast-TBL becomes a digital value set in the D / A data register of the channel 1 for contrast.

Regarding the luminance of the backlight, similarly to the contrast, the current backlight luminance level (Bac
The corresponding digital value (β) is acquired from the backlight look-up table (Backlight-TBL) based on (klight-Lvl) (step S5).
1) Set in the D / A data register of channel 0 (step S52). For example, in the case of the first power-on after resetting the keyboard controller 58, Bac
“3” is set in klight-Lvl. Therefore, the 1-byte value “77” located at the third byte from the top of the Backlight-TBL becomes a digital value set in the D / A data register of the channel 0 for backlight.

Finally, in order to start outputting an analog voltage converted from the digital value set in the D / A data register, the D / A control register is set to a D / A conversion output permission state (step S53). ).

By the above processing, the D / A output port of channel 1 (for contrast) based on 5 V which is the analog reference voltage of the keyboard controller 58
, And 1.5 V is output from the channel 0 D / A output port (for backlight luminance). By the way, the output voltage from the D / A output port is D / A
It is calculated by A data register value × 5V ÷ 255.

Power on state, that is, system DC / D
When the press of the power switch 5 is determined in the I / O service routine while the FET for the C converter is on, the power-off process is executed. First, a keyboard routine prohibition process is executed in order to execute a scan of the built-in keyboard 3 and communication with the BIOS. Specifically, the host interface interrupt is prohibited (step S54), and the key scan cycle timer is stopped (step S55).
Inhibit the host interface function (step S5
6). By disabling the host interface function, various signals connected to the ISA bus become invalid (electrically in a high-impedance state) and the ISA bus I / O addresses 66h, 62h, 64
Communication between the BIOS and the keyboard controller 58 via h and 60h is prohibited.

Further, the work RAM used in the keyboard service is initialized (step S57).
However, Panel-1D, Contrast-Lv, which are volume-related work areas of the LCD panel 11,
1, Contrast-TBL, / Backlight
Regarding the contents of -Lvl, Backlight-TBL, etc., data is retained even when the power is off. This is because when a user makes a fine adjustment of the backlight brightness and contrast of the LCD panel 11 in a keyboard service routine to be described later, the level adjusted by the user is maintained.

The keyboard controller 58 always operates when the AC adapter 101 or the battery pack 2 is connected as described above, and keeps the data in the internal RAM. The volume level of the LCD panel 11 does not change irrespective of the power ON / OFF switching. In other words, as long as the usage environment does not change, the user does not need to readjust each time of startup.

Finally, a process for preventing a leak current is executed. First, the I / O port connected to the system side by the ISA bus or the like is set in the input direction (S5).
8) After setting the D / A control register to the D / A output prohibited state (step S59), the system DC / D
The C-FET control signal is turned off, and the power supply to the system is stopped (step S60).

[Keyboard Service Routine] The keyboard service routine scans the built-in keyboard 3, communicates with an external mouse and an external full keyboard, transmits a corresponding key code to the BIOS, and receives various commands from the B1OS. Although there are various functions such as executing the command, the description will be limited to the process of receiving and executing various commands particularly related to the present invention and the process of scanning the built-in keyboard 3.

[Command Receiving and Execution Processing (Panel ID Notification Command Receiving Processing)] The processing of the keyboard controller 58 corresponding to the panel ID notification command during the POST processing by the B1OS will be described with reference to FIGS.

First, the BIOS stores 4B in the address of 66h.
When the value of h is I / O written, I / O is automatically performed by hardware built in the keyboard controller 58.
A BF (Input Buffer Full) flag is set, and a HIF (Host Inter Host Full) is set.
Face) An interrupt occurs.

HI in Keyboard Controller 58
In the F interrupt processing, the HI connected to the ISA bus
The value 4Bh is obtained from the F data register. Thus, the IBF flag is automatically cleared by the internal hardware of the keyboard controller 58. The keyboard controller 58 determines that this I / O write data is a panel ID notification command because it is writing to the I / O address of 66h, and holds the value “4Bh” in the command holding work (FIG. In step S81, a flag is set to 1 to indicate that the command has been received from the keyboard service routine (step S82), and the HIF interrupt process ends.

The BIOS checks the IBF flag by I / O reading 66h, and after confirming that the IBF flag has been cleared by the keyboard controller 58, writes the panel ID value to 62h by I / O. Here, a case where a 1D3 LCD panel is used will be described as a specific example. As described above, on the keyboard controller 58 side, the IBF flag is automatically set by built-in hardware, and a HIF interrupt occurs. In the HIF interrupt processing, the keyboard controller 58 acquires a panel ID value of 03h from the HIF data register connected to the ISA bus. Thereby, the IBF is automatically performed by the internal hardware of the keyboard controller 58.
The flag is cleared. Keyboard controller 58
Is a write to the I / O address of 62h, so this I / O write data is data (panel ID value)
Is determined, the value “03h” is held in the data holding work area (step S83), and a flag indicating that data has been received for the keyboard service routine is set to 1 (step S84). ), H
The IF interrupt processing ends.

Next, the keyboard service routine will be described with reference to FIG. The keyboard service routine is executed at a cycle of 1 msec. In this routine, a command execution process, a key scan process, a communication process with an external mouse or the like are executed.

In the command execution processing, first, the command reception completion flag set in step S82 is referred to (step S85). As a result, if the command received flag is “0”, the flow branches to another keyboard-related process. In the case of "1", the data reception completion flag set in step S84 is referred to (step S84).
86). As a result, if the data reception flag is "0", the process branches to another keyboard-related process. If the data reception flag is "1", the command execution process is performed. That is, the command execution process is executed when the command reception completed flag and the data reception completed flag are set to “1”.

First, the command received flag and the data received flag are cleared for the next command (S87), and a value is obtained from the command holding work area to determine the command (step S88). If the value acquired from the command holding work area is “4Bh”, this command is a panel ID notification command, so that panel ID notification command processing is executed.

That is, the value (x) is obtained from the data holding work area and compared with the value (y) held in the panel-ID work area (step S89).
If they are the same, the contents of the current look-up table can be continued, and the process branches to another keyboard-related process. If different, it means that the LCD panel 11 having a panel ID different from the panel ID 6 set in the initialization processing of the keyboard controller 58 is actually attached. Here, the case where “3” is set by the 4Bh command from B1OS (that is, L of panel ID3)
(When the CD panel 11 is attached).

First, the work RAM for the LCD panel executed in the initialization processing of the keyboard controller 58 is reconstructed (step S90). In this reconstruction process, Pa
"3" is set to the nel-ID (step S91),
The parameters (lookup table data and default level) for panel ID3 prepared in the ROM of the keyboard controller 58 in advance are stored in the Contras
t-TBL, Contrast-Lvl, Backli
ght-TBL and Backlight-Lvl are stored in each work area (steps S91 to S95).

Then, similarly to the FET control routine, Contrast-Lvl and Backlig
Contrast-TB with the value held in ht-Lvl
L, and the respective look-up tables of Backlight-TBL are referred to, the corresponding digital value is obtained, and D is obtained.
/ A data register (steps S96 to S9)
9).

With the above processing, taking the case of the first power-on after resetting the keyboard controller 58 as an example, the control is switched from the control for panel ID 6 to the control for panel ID 3. That is, as shown in FIG. 11, the default value of contrast is O
From 0.53 V corresponding to level 18 of 64 steps from V to 1.88 V, 1.70 V corresponding to level 28 of 64 steps from 1.53 V to 1.92 V
Switch to As for the backlight, eight levels from 0V to 3.3V to eight levels from OV to 1.8V are used.
It switches to stages and the default value switches from 1.89V to 1.03V.

After the above processing, the POS of the BIOS
As described in the T process, the backlight 12 of the LCD panel 11 is turned on. If the backlight 12 is not turned on, the difference in brightness and contrast of the backlight 12 cannot be recognized. Therefore, as described above, after the work RAM for the LCD panel is reconstructed, the LCD panel 1
1 by turning on the backlight 12 without making the user aware of the switching of the panel volume control accompanying the replacement of the LCD panel 11.
The LCD panel 11 that is currently connected starts up with the optimal volume voltage.

[Scanning process of built-in keyboard]
The scanning process of the built-in keyboard 3 related to the volume control of the LCD panel 11 will be described. However, the scan processing of the built-in keyboard 3 includes key detection processing,
Although there is a delay process from the detection of the press to the confirmation, etc., only the key detection process related to the present invention will be described.

In this embodiment, for the built-in keyboard 3 having 89 keys, 8 × 8 lines with 16 scanout lines and 8 return lines (key inline) are used.
Pressed keys are detected by using 16 scan matrices. Specifically, for a scan matrix designed as shown in FIG. 12, 15 scan outlines are sequentially driven one by one at a period of 10 msec. Then, the return line when driving to Low is checked, and a return signal of Low is detected. For example, if the fifth return line of the scan outline is driven low and the sixth return line is low, then 65
Pressing of the key corresponding to h (that is, the ENTER key) is detected. That is, each of the 89 keys has a return line No. × 10h + scan outline N
o. As the number from 00h to 7Fh calculated by
It will be recognized by the keyboard controller 58.

In this embodiment, as described above, the volume control of the LCD panel 11 is assigned to the following keys. That is, Fn + F5 → increase of backlight luminance, Fn−10F6 → decrease of backlight luminance, Fn
+ F7 → contrast up, Fn + F8 → contrast down. As shown in FIG. Is Fn (50
h), F5 (0Dh), F6 (1Eh), F7 (0E
h), F8 (0Bh).

The built-in keyboard 3 configured as described above
On the other hand, a key scan process executed at a cycle of 10 msec will be described with reference to FIGS.

First, the current scan outline No.
Is acquired from the work area (scanout No.) (step S100), and the scanout line of the acquired number is driven low (step S101), and
Regarding the return line of the book, the return line No. of the low status. Is searched (step S102).
With the above processing, the detection of the pressed key is completed, and the scan-out number is set for the next key scan. Is incremented by 1 (step S103). However, since the scan outline is from No. 0 to No. 15, if the result of adding 1 is 16 or more, it is reset to 0.

Next, the scan-out No. acquired in step S100. Is determined to be "5" (step S104). As a result, the scan-out No. Is not "5", the process proceeds to step S108. Scan out No. Is "5", a flag update process for the Fn key is executed before proceeding to step S108. That is, it is determined whether or not the status of the 0th return line to which the Fn key is assigned is Low (step S105). If the status of the 0th return line is Low, the Fn key is pressed. The Fn-On flag is set (step S106), and in the case of High, the Fn-On flag is cleared (step S107) assuming that the Fn key is not pressed, and the process proceeds to step S108.

In step S108, step S102
The presence / absence of a pressed key is determined based on the search result in step (1).
As a result, if there is no pressed key, the process branches to another process in the keyboard service routine. On the other hand, if there is a pressed key, the status of the Fn-0n flag is checked (step S109). As a result, when the Fn-0n flag is 0, the key code corresponding to the pressed key is notified to the BIOS as in the general key scan processing (step S122).

On the other hand, if the Fn-0n flag is "1", it is checked whether or not the pressed key is a volume-related key from the F5 key to the F8 key. Proceed to S122. When the pressed key is a volume-related key from the F5 key to the F8 key, a volume change process corresponding to each key described below is executed.

That is, the pressed key No. Is ODh, that is, when the F5 key and the Fn key are pressed at the same time, the backlight brightness level is increased. First, the content held in the Backlight-Lv1 is incremented by one (step S110). However,
As described above, in this embodiment, the maximum level is 7, and if the maximum level is already 7, the value is continued. next,
Similar to the processing when the system DC / DC converter 73 is on,
Backlight-Backlight from the beginning of TBL
One-byte data (v) stored at the byte position indicated by ht-Lvl is obtained (step S11).
1) The data v is set in the D / A data register of channel 0 (step S112). As a result, after the elapse of the conversion time specified by the hardware of the keyboard controller 58, the output is switched to the analog output voltage corresponding to the digital value (v), and the output voltage of the backlight luminance control signal 60 increases. The backlight 12 becomes brighter by one level.

Pressed key No. Is 1Eh, that is, F
If the 6 key and the Fn key are pressed at the same time, the backlight brightness level is reduced. First, B
The content held in acknowledgment-Lv1 is decremented by 1 (step S113). However, since the minimum level is 0 in the present embodiment as described above,
If so, continue with that value. Next, the system DC
As with the processing when the / DC converter 73 is turned on, the Backli
Backlight-Lvl from the beginning of ght-TBL
The 1-byte data (w) stored at the byte position of the number indicated by is obtained (step S114), and this data w is set in the D / A data register of channel 0 (step S115). As a result, after the conversion time specified by the hardware of the keyboard controller 58 elapses, the analog output voltage is switched to the analog output voltage corresponding to the digital value (w), and the output voltage of the backlight luminance control signal 60 decreases. The backlight 12 becomes darker by one level.

Pressed key No. Is OEh, that is, F
If the 7 key and the Fn key are pressed at the same time, the contrast level is increased. First, Con
The content held in trust-Lv1 is incremented by one (step S116). However, as described above, the maximum level is 63 in the present embodiment, and if the maximum level is already 63, the value is continued. Next, the system DC / D
Similar to the processing when the C converter 73 is on, Contrast
-Obtain 1-byte data (x) stored at the byte position indicated by Contrast-Lvl from the beginning of the TBL (step S117), and set this data x in the D / A data register of channel 1 (step S117). Step S118). As a result, the keyboard controller 5
After the conversion time specified by the hardware of No. 8 has elapsed,
Switching to an analog output voltage corresponding to the digital value (x), the output voltage of the contrast control signal 61 increases,
From the viewpoint of the user, the contrast is increased by one level.

Pressed key No. Is OBh, that is, F
If the 8 key and the Fn key are pressed at the same time, the contrast level is reduced. First, Con
The content held in trust-Lv1 is minus one.
(Step S119). However, since the minimum level is 0 in the present embodiment as described above, if the minimum level is already 0, the value is continued. Next, the system DC / DC
Similar to the process when the converter 73 is on, the Contrast-
1-byte data (y) stored at the byte position indicated by Contrast-Lvl from the beginning of the TBL is acquired (step S120), and this data y is set in the D / A data register of channel 1 (step S120). S121). As a result, the keyboard controller 5
After the conversion time specified by the hardware of No. 8 has elapsed,
Switching to the analog output voltage corresponding to the digital value (y), the output voltage of the contrast control signal 61 decreases,
From the viewpoint of the user, the contrast is reduced by one level.

After the above-described volume-related processing is executed, the process proceeds to the next keyboard service processing without performing the processing of step S122.

As described above, control parameters for controlling the backlight brightness and contrast corresponding to various LCD panels are stored, and the type of the LCD panel is detected by detecting the type of the LCD panel. Default values for volume control of backlight brightness and contrast are automatically set based on the control parameters for the LCD panel, and when an instruction to change the backlight brightness and contrast is given, it corresponds to the detected type. The backlight luminance and contrast are changed in accordance with the above change instruction with reference to the control parameters for the LCD panel to be changed.

Therefore, it is possible to always set appropriate backlight brightness and contrast default values for volume control regardless of the type of the mounted LCD panel, and even if the type of the mounted LCD panel is changed. The necessity of performing fine adjustment can be reduced. Also, when adjusting the backlight brightness and contrast in response to the instruction, the adjustment can be performed with an appropriate adjustment amount per one step according to the type of the LCD panel.

Note that the present invention is not limited to the above embodiment, and it is also possible to issue an instruction for adjusting the volume of the backlight luminance and the contrast using an input device other than the built-in keyboard. For example, FIG.
As shown in (1), it is also possible to issue a volume adjustment instruction for the backlight luminance and the contrast by operating the remote controller. In this case, as shown in FIG.
A volume change request input from the
S or an application may be notified, and a volume change command may be issued to the KBC via the BIOS.
Alternatively, the BIOS can directly issue a volume change command to the KBC without notifying the OS or the application.

In addition to the change of the LCD unit during the production and the correspondence to a plurality of models due to the difference of the LCD panel, as shown in FIG. 16, the portable information processing which allows the user to freely replace the LCD unit itself. The present invention can be applied to an apparatus.

[0105]

As described above, according to the present invention,
In an information processing apparatus including a liquid crystal display panel, a detection unit for detecting a type of the liquid crystal display panel, and a storage unit for storing at least a control parameter for controlling a backlight luminance / contrast for each type of the liquid crystal display panel Selection means for selecting a control parameter corresponding to the type of the liquid crystal display panel detected by the detection means from at least the control parameters stored in the storage means, and a control parameter selected by the selection means. Control means for controlling the backlight brightness / contrast of the liquid crystal display panel based on the
Volume control can be appropriately performed on any of a plurality of liquid crystal display panels having different volume control characteristics of backlight luminance and contrast.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electrical schematic configuration of a notebook PC according to an embodiment of the present invention.

FIG. 2 is a perspective view of the notebook PC.

FIG. 3 is a block diagram showing a detailed configuration centering on a keyboard controller.

FIG. 4 is a flowchart showing a POST process by the BIOS.

FIG. 5 is a flowchart showing an outline of processing by a keyboard controller.

FIG. 6 is a flowchart illustrating an initialization process performed by a keyboard controller.

FIG. 7 is a flowchart showing FET control by a keyboard controller.

FIG. 8 is a flowchart continued from FIG. 7;

FIG. 9 is a flowchart illustrating HIF interrupt processing by a keyboard controller.

FIG. 10 is a flowchart showing processing of a keyboard controller when receiving a panel ID.

FIG. 11 is a diagram illustrating a specific example of a process performed by a keyboard controller when a panel ID is received.

FIG. 12 is a diagram showing a key scan matrix of a built-in keyboard.

FIG. 13 is a flowchart illustrating key scan processing related to volume control of backlight luminance and contrast.

FIG. 14 is a flowchart continued from FIG. 13;

FIG. 15 is an image diagram showing a first modification of the embodiment.

FIG. 16 is an image diagram showing a second modified example of the embodiment.

FIG. 17 is a block diagram showing a first conventional example.

FIG. 18 is a block diagram showing a second conventional example.

FIG. 19 is an image diagram showing the problem of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PC main body 2 Battery pack 3 Built-in keyboard 11 LCD panel 12 Backlight 13 Inverter 14 LCD board (with ID) 55 BIOSROM 58 (H8) Keyboard controller 58a D / A converter 58b Internal ROM 60 Backlight brightness control signal 61 Contrast control Signal 72 Keyboard DC / DC converter 101 AC adapter

Claims (21)

[Claims] 1. An information processing apparatus having a liquid crystal display panel, comprising: detecting means for detecting the type of the liquid crystal display panel; and control parameters for controlling at least the backlight luminance and contrast for each type of the liquid crystal display panel. Storage means for storing a control parameter corresponding to the type of the liquid crystal display panel detected by the detection means from at least the control parameters stored in the storage means; and selection by the selection means. Control means for controlling the backlight brightness / contrast of the liquid crystal display panel based on the obtained control parameters. 2. The storage unit stores an initial level together with a plurality of control parameters for each control level as the control parameter for each type of the liquid crystal display panel, and the selection unit stores the initial level. Selecting a control parameter and an initial level corresponding to the type of the liquid crystal display panel detected by the detection means from among the control parameters and the initial level, wherein the control means selects the control parameter selected by the selection means; 2. The information processing apparatus according to claim 1, wherein a control parameter corresponding to the initial level is initially set. 3. The control means selects a control parameter and an initial level corresponding to a predetermined liquid crystal display panel when the power is turned on, and the control means responds to the initial level among the control parameters selected when the power is turned on. Control parameters to be set as default values, and when the liquid crystal display panel detected by the detection means is different from the predetermined liquid crystal display panel, the control parameters corresponding to the type of the liquid crystal display panel detected by the detection means 2. The information processing apparatus according to claim 1, wherein among the control parameters selected by the selection unit, a control parameter corresponding to an initial level is set again as a default value. 4. A power-on control means for turning on the power to the backlight after the execution / non-execution of the control parameter resetting process based on the detection result by the detection means is completed. Item 10. The information processing apparatus according to Item 1. 5. The control unit according to claim 1, wherein the control unit changes the default value within a range of the control parameter selected by the selection unit in response to an operation of a predetermined operation unit. Information processing device. 6. A level storage means for holding a current level of a control parameter set by said control means even when the information processing apparatus is not powered on. An information processing apparatus according to claim 1. 7. The keyboard controller according to claim 1, wherein said storage means, selection means, control means, power-on control means, and level storage means are built in a keyboard controller.
An information processing apparatus according to claim 1. 8. An information processing apparatus provided with a liquid crystal display panel, a detecting step of detecting a type of the liquid crystal display panel, and a control parameter for controlling at least a backlight luminance / contrast for each type of the liquid crystal display panel. A selecting step of selecting a control parameter corresponding to a type of the liquid crystal display panel detected by the detecting step from at least the control parameters stored by the storing step; and selecting by the selecting step. Controlling a backlight brightness / contrast of the liquid crystal display panel based on the obtained control parameters. 9. The storage step stores an initial level together with a plurality of control parameters for each control level as the control parameter for each type of the liquid crystal display panel, and the selection step is stored by the storage step. Selecting the control parameter and the initial level corresponding to the type of the liquid crystal display panel detected by the detection step from among the control parameters and the initial level, wherein the control step selects the control parameter selected by the selection step 9. The backlight brightness / contrast control method according to claim 8, wherein a control parameter corresponding to the initial level is initially set. 10. The selecting step selects a control parameter and an initial level corresponding to a predetermined liquid crystal display panel when the power is turned on, and the control step corresponds to an initial level among the control parameters selected when the power is turned on. Control parameters to be set as default values, and when the liquid crystal display panel detected in the detection step is different from the predetermined liquid crystal display panel, the control parameter corresponding to the type of the liquid crystal display panel detected in the detection step 9. The backlight brightness / contrast control method according to claim 8, wherein the control parameter corresponding to the initial level among the control parameters selected in the selecting step is set again as a default value. 11. A power-on control step of turning on the power to the backlight after the execution / non-execution of the control parameter reset processing based on the detection result in the detection step is completed. Item 10. A backlight brightness / contrast control method according to Item 8. 12. The control method according to claim 8, wherein the control step changes the default value within a range of the control parameter selected in the selection step in response to an operation of a predetermined operation means. Backlight brightness / contrast control method. 13. The information processing apparatus according to claim 8, further comprising a level storing step of retaining a current level of a control parameter set by said control unit even when the information processing apparatus is not powered on. The backlight brightness / contrast control method described in the above. 14. The storage step, the selection step, the control step,
9. The backlight brightness / contrast control method according to claim 8, wherein the power-on control step and the level storage step are executed by a keyboard controller. 15. A storage medium storing a program for controlling a backlight brightness / contrast of a liquid crystal display panel mounted on an information processing device, wherein the program detects a type of the liquid crystal display panel. A storage routine for storing at least a control parameter for controlling backlight luminance / contrast for each type of the liquid crystal display panel; and a detection routine for detecting at least the control parameters stored in the storage routine. And a control routine for controlling the backlight brightness / contrast of the liquid crystal display panel based on the control parameters selected by the selection routine. Storage medium characterized by the following: . 16. The storage routine stores an initial level together with a plurality of control parameters for each control level as the control parameters for each type of the liquid crystal display panel,
The selection routine selects a control parameter and an initial level corresponding to the type of the liquid crystal display panel detected by the detection routine from among the control parameters and the initial level stored by the storage routine. The storage medium according to claim 15, wherein the routine initializes a control parameter corresponding to an initial level among the control parameters selected by the selection routine. 17. The method according to claim 1, wherein when the power is turned on, a control parameter corresponding to a predetermined liquid crystal display panel,
Selecting an initial level, the control routine sets, as a default value, a control parameter corresponding to the initial level among the control parameters selected at power-on, and the liquid crystal display panel detected by the detection routine and the predetermined liquid crystal. If the display panel is different, the control parameter corresponding to the initial level among the control parameters selected by the selection routine is set again as a default value as the control parameter corresponding to the type of the liquid crystal display panel detected by the detection routine. The storage medium according to claim 15, wherein: 18. A power-on control routine for turning on the power to the backlight after the execution / non-execution of the control parameter resetting process based on the detection result by the detection routine is completed. Item 16. The storage medium according to Item 15. 19. The control routine according to claim 15, wherein the control routine changes the default value within a range of the control parameter selected by the selection routine in response to an operation of a predetermined operation means. Storage medium. 20. A system according to claim 15, further comprising a level storage routine for retaining a current level of a control parameter set by said control means even when the information processing apparatus is not powered on. The storage medium according to the above. 21. The storage medium according to claim 15, wherein said storage routine, selection routine, control routine, power-on control routine, and level storage routine are executed by a keyboard controller.