JP2656267B2 - Display control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention] (Industrial application field) The present invention is directed to a personal computer which is equipped with a flat panel display unit such as a plasma display unit as a standard, and is capable of arbitrarily connecting a color display unit. The present invention relates to a display control device suitable for use in constructing a computer system such as a computer and a personal workstation.

(Prior art) Conventionally, a plasma display unit is standard equipment,
A color display unit can be connected arbitrarily.
2. Description of the Related Art In a computer system such as a personal computer and a personal workstation, when data to be handled has a color element, it is impossible to express data for each color by a display using a plasma display unit.

Conventionally, when performing gradation display in a plasma display, display information is provided with a gradation by thinning out display dots, blinking, or the like, but such a so-called pseudo gradation display means uses a color display in a color display. However, there is a problem that it is not possible to display a distinction such as a color display.

Therefore, in a system equipped with a plasma display unit as standard equipment and a color display unit that can be connected arbitrarily, it is possible to display data classified by color on the color display by changing the gradation on the plasma display. It is possible, but at this time,
Color display using CRT (hereinafter simply referred to as CRT)
When display drive control is performed by a single display controller (CRTC), if the display luminance level of the CRT is directly associated with a plasma display (hereinafter, referred to as a PDP), the following inconvenience occurs. That is, the brightness of the PDP is generally C
Setting the PDP display brightness higher than the normal brightness level, like the CRT brightness, lowers the brightness of the normal display and lowers the brightness of the normal display, making it difficult to see the display screen. Occurs.

(Problems to be Solved by the Invention) As described above, conventionally, in a system in which a PDP is provided as standard and a CRT can be arbitrarily connected, data that is color-coded and displayed on the CRT is displayed in gradations by the PDP. When I tried, C
If the display brightness level of the RT is directly associated with the PDP, there is a problem that the brightness at the time of the normal display on the PDP becomes low and the display screen becomes difficult to see.

The present invention is to display a data having a display element for each color handled by a color display when a gradation display is performed on a flat display in association with a color so as to avoid a decrease in luminance during normal display by replacing a specific luminance level. An object of the present invention is to provide a display control device that makes it easy to see a screen.

[Constitution of the Invention] (Means and Action for Solving the Problems) The present invention relates to a display control device for controlling the display of a flat display panel. A color conversion table having a second block for performing gradation conversion; and means for exchanging the first block and the contents of the color conversion table with the contents of the second block. In this configuration, high-brightness gradation conversion is performed in the first block for performing, and thereby, data having color-specific display elements handled by a color display is displayed in gradation on a flat display in association with colors. At this time, the high-luminance display level and the normal luminance level are interchanged to ensure appropriate luminance during normal display, making it easier to see the display screen.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.
Here, a display control mechanism having a so-called common pallet structure in which a color display unit and a plasma display unit are selectively driven for display by using a common pallet will be described as an example.

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention.

In the figure, reference numerals 11 and 12 denote pallet data buffers for storing pallet data under the control of a CPU which controls the system, respectively. Of these, 11 denotes a pallet data buffer for a color CRT display (hereinafter, referred to as a main memory). CRT pallet data buffer).
Reference numeral 2 denotes a pallet data buffer for a plasma display (hereinafter referred to as a PDP pallet data buffer) placed on the main memory.

Reference numeral 13 denotes a palette in which pallet data corresponding to the currently used display is set under the control of the CPU and performs color conversion or color → gradation conversion in accordance with the pallet data. When the plasma display is to be driven, the pallet data stored in the PDP pallet data buffer 12 is set, and the pallet data stored in the PRT pallet data buffer 11 is set. When pallet data is set [16
When performing color conversion of [color → 64 colors] (16 colors × 4 gradations) and setting PDP palette data [16 colors → 4 gradations]
Color → gradation conversion.

Reference numeral 14 denotes a video RAM (hereinafter referred to as V-RAM) for storing display data, which has a 4-plane (16 colors) structure here.
15 is the default value of the pallet for CRT (D / CRT) and PDP
BIOS that stores the default values (D / PDP) of the palette
· ROM, where the default value of the PDP palette (D · PDP) is the default value D · PDP (N) for normal display according to CRT display, high brightness display level (gray level 3) and normal brightness It has a default value D · PDP (R) for reverse display in which the level (gray level 2) is replaced.

Reference numeral 20 denotes a color which receives display data in 6-bit units converted by the palette 13 and displays 64 colors.
CRT display device (hereinafter simply referred to as CRT), 30
Is a plasma display device (hereinafter, simply referred to as a PDP) that performs display of four gradations by receiving display data (R, G) in 2-bit units converted from color to gradation by the palette 13.
It is.

FIG. 2 shows a memory map of the entire system in the above embodiment. Here, each pallet data buffer on the main memory directly related to the embodiment of the present invention.
11 and 12, and only the V-RAM 14 and the BIOS ROM 15 are shown, and the description of the other areas is omitted.

FIG. 3 shows the structure of the pallet 13 described above.
6-bit display data (R, G, B, SR, SG, S
In B), SR, SG, SB are R, G, B auxiliary bits. Here, of the 6-bit display data (R, G, B, SR, SG, SB), two bits of R (RED) and G (GREEN) are used as PDP display data of the PDP 30 shown in FIG. Guided to the interface circuit.

FIG. 4 shows an interface circuit of the PDP 30. Two-bit PDP display data of R (RED) and G (GREEN) inputted from the palette 13 shown in FIG. → P) 31 and 32, each is converted to 4-bit data (PH1 to PH4, PL1 to PL4), and is displayed as 8-bit 4-gradation display data via a 4-gradation display drive circuit (not shown). Supplied to

FIG. 5 is a flowchart showing a display processing flow in the above embodiment, and FIG. 6 is a flowchart showing the setup processing routine (step S1) of FIG. 5 in more detail.

FIG. 7 is a diagram for explaining the display drive control means of the PDP 30 in the above embodiment, and FIG. 7 (a) shows a default value D · PDP (N) for normal display in which CRT display and luminance level are combined. (B) showing the setting order (gray level 3 = maximum luminance, gray level 0 = minimum luminance) of luminance-gradation level in gradation display (hereinafter, referred to as A method) according to FIG.
Is the default value D · for the reverse display in which the high luminance level (gray level 3) and the normal luminance level (gray level 2) are interchanged.
FIG. 3C is a diagram showing the setting order of luminance-one gradation level in gradation display according to PDP (R) (hereinafter, referred to as B method). FIG. 4C shows the relationship between the display default values of the A method and the B method. It is a figure shown in comparison. In FIG. 7C, when the output display data of the V-RAM 14 is, for example, 7H (“0111”) representing “white” of the normal luminance level, the palette 13 contains P-type palette data for the A system. Is set, the display data of the normal luminance level [2] (R = "1", G = "0") is displayed on the PDP30.
Indicates that the display data at the high luminance level [3] (R = “1”, G = “1”) is transmitted to the PDP 30 when the B-type PDP palette data is set. .

Here, the operation of the embodiment will be described with reference to FIGS. 1 to 7.

When starting up the system by turning on the power,
Under the control of U, the default values of the PDP palette and CRT palette stored in the BIOS ROM 15 (D / CRT, D / PD
P) Palette data buffer 1 for CRT in main memory
1, and loaded into the PDP pallet data buffer 12 (step S1 in FIG. 5).

The processing at this time will be described in more detail with reference to FIG. In the system startup processing at power-on, the CPU
Under the control of, the reverse display flag of the specific state setting register in the setup RAM holding the data by the battery backup is referred to (step S1 in FIG. 6).
1). If the above flag indicates the reverse display mode, the reverse display default value D / PDP in the BIOS ROM 15 is displayed.
(R) is P in the main memory as PDP pallet data.
The data is loaded into the DP pallet data buffer 12 (steps S12 and S13 in FIG. 6). If the flag does not indicate the reverse display mode, the default value D.PDP (N) for the normal display in the BIOS ROM 15 is set. It is loaded into the PDP palette data buffer 12 in the main memory as PDP palette data (steps S12 and S14 in FIG. 6). After loading the palette data into the PDP palette data buffer 12, the default value of the CRT palette in the BIOS / ROM 15 (D
・ CRT) in the main memory as pallet data for CRT
Loaded into the CRT pallet data buffer 11 (6th
Figure Step S15).

In this way, the palette data for the PDP and the palette data for the CRT stored in the BIOS ROM 15 are set in the palette data buffer 12 for the PDP and the palette data buffer 11 for the CRT.

Here, when no selection selection command of the display is input or when a selection selection command of the PDP 30 is newly input, the PDP pallet data buffer 1
The palette data stored in the PDP 30 is loaded into the palette 13 and the display data stored in the V-RAM 14 is subjected to [16 colors → 4 gradations] → gradation conversion using the palette data. And is displayed (step S in FIG. 5).
2, S3).

The display operation at this time will be described with reference to FIG. 3 and FIG. Read from V-RAM 14 and [16
R → RED and G (G) shown in FIG.
REEN) 2-bit display data for PDP is the PDP shown in Fig. 4.
The data is guided to the interface circuit 30 and converted into 4-bit (4-pixel unit) data (PH1 to PH4, PL1 to PL4) by serial-parallel conversion circuits (S → P) 31 and 32, respectively, for a total of 8 bits. The display data is supplied to the display panel via a four-gradation display driving circuit (not shown) as display data of four pixels and four gradations. Here, when the 2-bit PDP display data (R, G) output from the palette 13 is "0, 0", the discharge pulse width for the Y electrode drive 1H period is set to the lowest duty ratio of 10%, Then, at “0,1”, 40%,
It is 70% for "1,0" and 100% for "1,1".

At this time, when the P-type palette data for the A system is set in the palette 13, the bit contents (R, G) of the PDP display data output from the palette 13 are directly reflected on the luminance. Key, but the palette 13
When the B-type PDP pallet data is set, the bit contents (R, G) of the PDP display data output from the pallet 13 are not directly reflected on the luminance, and the high luminance level and the normal luminance level are not reflected. The display data output of is replaced,
Display data of a normal luminance level (for example, 7H;
When “0111”) is output, it indicates the highest luminance.
Display data for PDP of gradation level 3 (R = "0", G = "1")
Is output from the pallet 13.

Thereby, the data displayed at the normal luminance on the CRT 20 is displayed at the highest display luminance on the PDP 30 having a lower luminance than the CRT 20, so that, for example, the display of text characters is clearly visible on the PDP 30. It is displayed in the state.

In the display mode using the PDP 30, when a command and palette data for changing the correspondence between colors and gradations are input by the user, the contents of the palette 13 are synchronized under the control of the CPU. Rewritten according to the input data,
After that, according to the rewritten PDP pallet data, [1
Color → gradation conversion of “6 colors → 4 gradations” is performed (steps S4 and S5 in FIG. 5). Also, when the switching designation of the A method / B method is input, the contents of the pallet 13 are rewritten according to the same input data under the control of the CPU.
Color → gradation conversion of [16 colors → 4 gradations] is performed according to the pallet data. At this time, the content of the reverse display flag of the specific status setting register in the setup RAM is also rewritten according to the above switching.

When a command to switch the display device to be used from the PDP 30 to the CRT 20 is input by the designation of the soother, the CRT pallet data buffer 11 is controlled under the control of the CPU.
Is read-accessed, the contents of the pallet 13 are rewritten according to the CRT pallet data read from the pallet data buffer 11, and thereafter, the display data read from the V-RAM 14 is rewritten according to the rewritten CRT pallet data. After the color conversion of [16 colors → 64 colors] is performed, it is displayed on the CRT 20 (steps S6 to S8 in FIG. 5).

In the display mode of the CRT 20, when a palette color change designation command and palette selection designation information for changing the correspondence relationship of [16 colors → 64 colors] are input by the user, the CPU Under the control, the palette 13 is rewritten by the application software, and thereafter, the color conversion of [16 colors → 64 colors] is performed according to the palette color of the rewritten CRT palette data (step in FIG. 5). S9, S10).

Here, when a command to switch the display device to be used from the CRT 20 to the PDP 30 is input by the user's specification, the PDP pallet data buffer 12 is read-accessed under the control of the CPU, and the contents of the pallet 13 are read. Is rewritten according to the PDP pallet data read out from the pallet data buffer 12, and thereafter, the display data read out from the V-RAM 14 is changed to [16 colors → 4 gradations] according to the rewritten PDP pallet data. → After gradation conversion,
It is displayed on the PDP 30 (steps S11, S2, S3,... In FIG. 5).

As described above, by using the palette 13 common to the CRT 20 and the PDP 30, information displayed by color on the CRT 20 can be displayed on the PDP 30 in multiple gradations with an arbitrary color → gradation correspondence.

In addition, as the PDP palette data, any one of the A method according to the CRT display or the B method in which the high luminance level and the normal luminance level are interchanged is arbitrarily selected according to the display content (for example, graphic display, text display, etc.). Therefore, data that is displayed at normal brightness on the CRT 20 can be displayed at the highest display brightness on the PDP 30 that is lower in brightness than the CRT 20.
It is displayed in a clearly legible state above.

In the above embodiment, a display control mechanism having a so-called common pallet structure in which the color display unit and the plasma display unit are selectively driven by using a common pallet has been described. Even in the case where the display pallets are independently provided, display control by the same color → gradation correspondence as described above is possible, and the configuration and operation at this time can be easily understood from the above embodiment. Therefore, the detailed description is omitted here.

Further, in the above embodiment, the PDP 30 is configured to drive four gradation display, and the high luminance level-the normal luminance level is selectively switched. However, the number of PDP display gradations and the luminance level to be switched are set. The present invention can be easily realized even in cases other than the above embodiments.

[Effects of the Invention] As described above in detail, according to the display control method of the present invention,
A flat display unit is provided as standard, and other display objects, for example, a color display unit using a CRT can be connected arbitrarily. Between the display unit, a brightness level conversion mechanism for interchanging the brightness level of the display pixel information is interposed, and the flat display panel is configured to display control according to the brightness level converted by the brightness level conversion mechanism. When data with color-specific display elements handled by a color display is displayed in gradation on a flat display in association with colors, the high-luminance display level and the normal luminance level are exchanged to secure the proper luminance for normal display. , Make the display screen easier to see It can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of one embodiment of the present invention, FIG. 2 is a diagram showing a memory map on a system in the above embodiment, and FIG. 3 is a configuration of a pallet in the above embodiment. FIG. 4 is a block diagram showing the configuration of the PDP interface circuit in the above embodiment, FIGS. 5 and 6 are flowcharts showing the display processing flow in the above embodiment, and FIG. FIG. 7 is a diagram for explaining display drive control of a PDP in the embodiment. 11… CRT palette data buffer, 12… PDP palette data buffer, 13… Palette, 14… Video RA
M (V-RAM), 15 BIOS ROM, 20 Color CRT display device (CRT), 30 Plasma display device (PDP), 3132 Serial-parallel conversion circuit (S
→ P) 、 D ・ PDP …… Default value of PDP pallet, D
・ PDP (N): Default value for normal display, D ・ PDP
(R): Default value for reverse display, D / CRT: Default value for CRT palette.

Claims (2)

(57) [Claims] 1. A display control device for controlling display of a flat display panel, comprising: a color conversion table having a first block for performing normal luminance gradation conversion and a second block for performing high luminance gradation conversion; Means for exchanging the contents of the first block and the contents of the second block of the color conversion table with each other, and performing high-brightness gradation conversion in the first block for performing normal-brightness gradation conversion A display control device characterized by the above-mentioned. 2. A method according to claim 1, wherein said means for exchanging the contents of said first block and the contents of said second block performs said exchange when a high-brightness gradation conversion mode is designated. 2. The display control device according to claim 1.