JPH08314417A - Liquid crystal driving method - Google Patents

Abstract

PURPOSE: To provide a liquid crystal driving method capable of optionally setting a display character width (five dots width/character or six dots width/ character) of respective rows with software control by an instruction command in a character dot LCD controller/driver LSI of a multi-row display. CONSTITUTION: A display control block 12 initializes a setting item related to various display functions of an LCD 18 based on various instructions (clear command, stand-by command, system set command, dot shift command, test mode command, etc.) inputted from an interface block 13, and executes display control of a character multi-row displayed on the LCD 18 based on the initialization item (setting item of the presence of a dot display character width and a horizontal dot shift set at every display row).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal driving method,
More specifically, the present invention relates to a liquid crystal driving method for controlling a dot display width when a character is displayed on a liquid crystal panel with a dot configuration.

[0002]

2. Description of the Related Art In a conventional liquid crystal driving method of a liquid crystal panel for displaying a character having a dot configuration, a character dot LCD controller / driver LSI used for controlling the drive controls a display character width of a character displayed in a dot configuration. All the lines in which the characters of the dot configuration (the number of vertical dots × the number of horizontal dots) are displayed are displayed with the width of 5 dots or the width of 6 dots set, for example.

In each setting of the display character width, the 5-dot character width is used as a normal display, and the 6-dot character width is used as a dot shift display and a detailed display. In the dot display character width control of the character displayed on such a liquid crystal panel, the instruction (software) used in the character dot LCD controller / driver LSI specifies 5 dot width / 6 dot width. The display character width can be set.

[0004]

However, in such character dot display character width control by the conventional character dot LCD controller / driver LSI, all the lines in which the character of the dot structure is displayed are the same. Since it was displayed with the display character width, there were the following problems.

That is, for example, when it is desired to perform the dot shift function (smooth scroll) only on an arbitrary line, it is sufficient to set the width of the arbitrary dot to a 6-dot character. In the width control, there is a problem in that all lines are set to a 6-dot character width even in a line where dot shift is not performed, and the number of apparent display digits is reduced.

An object of the present invention is to provide a multi-line display character dot LCD controller / driver LSI,
It is an object of the present invention to provide a liquid crystal driving method capable of arbitrarily setting the display character width (5 dot width / character or 6 dot width / character) of each line by software control by an instruction command.

[0007]

According to the first aspect of the present invention,
In a liquid crystal drive method for displaying the liquid crystal panel based on display data and various instruction signals output by the control means, a control means for driving and controlling a liquid crystal panel having at least a plurality of rows and a plurality of columns, , The display row for displaying the display data on the liquid crystal panel, the setting of the display width of the display data on the display row, and the presence / absence of horizontal shift of the display data on the display row are set. The display data is displayed on the liquid crystal panel based on the display width of the display data set and the presence / absence of horizontal shift.

According to a second aspect of the present invention, the liquid crystal panel is controlled based on control means for driving and controlling the liquid crystal panel having at least a plurality of rows and a plurality of columns, and display data and various instruction signals output by the control means. In the liquid crystal driving method for displaying, setting of a display line for displaying the display data on the liquid crystal panel by the control means, setting of a display width of the display data on the display line, and display of a double-width display data on the display line are performed. Presence / absence is set, and the display data is displayed on the liquid crystal panel based on the display width of the display data set in the display row and the presence / absence of the double-width display.

[0009]

According to the first aspect of the invention, the liquid crystal panel is controlled based on the control means for driving and controlling the liquid crystal panel having at least a plurality of rows and a plurality of columns, and the display data and various instruction signals output by the control means. In a liquid crystal driving method for displaying a panel, the control means sets a display line for displaying display data on the liquid crystal panel, a display width of display data on the display line, and a horizontal display data on the display line. The presence / absence of the direction shift is set, and the display data is displayed on the liquid crystal panel based on the display width of the display data set in the display row and the presence / absence of the horizontal shift.

Therefore, the display width of the display data is set for each display line in the liquid crystal panel, and it becomes possible to display a mixture of rows that are horizontally shifted and rows that are not horizontally shifted, so that various character displays can be expressed and dot display can be performed. It is possible to more effectively use the display column line of the liquid crystal panel when performing.

According to the second aspect of the present invention, the liquid crystal is controlled based on the control means for driving and controlling the liquid crystal panel having at least a plurality of rows and a plurality of columns, and the display data and various instruction signals output by the control means. In a liquid crystal driving method for displaying a panel, setting of a display line for displaying display data on the liquid crystal panel by the control means, setting of a display width of display data on the display line, and horizontal double angle of display data on the display line. The presence / absence of the display is set, and the display data is displayed on the liquid crystal panel based on the display width of the display data set in the display row and the presence / absence of the double-width display.

Therefore, the display width of the display data is set for each display line in the liquid crystal panel, and it becomes possible to display the double-width display line / the non-double-width display line in a mixed display. It is possible to more effectively use the display column line of the liquid crystal panel when performing.

[0013]

Embodiments of the present invention will be described in detail below with reference to FIGS. (First Embodiment) FIGS. 1 to 11 are views showing a first embodiment of a liquid crystal display device to which the present invention is applied. First, the configuration will be described. FIG. 1 is a diagram showing a block configuration of a display control unit 10 of the liquid crystal display device of this embodiment.

In FIG. 1, the display control unit 10 of the liquid crystal display device includes a power supply block 11 and a display control block 1.
2, an interface block 13, a display data memory block 14, a data gradation control block 15, a common driver 16, a segment driver 17 and an LCD 19.

The power supply block 11 contains a DC-DC converter, an LCD drive voltage generation circuit, etc., and generates a control voltage and a drive voltage based on a reference voltage supplied from a battery (not shown) or the like. , Display control block 12,
It is supplied to the common driver 16 and the segment driver 17.

The display control block 12 is a CPU (Ce that controls the common driver 16 and the segment driver 17).
ntral processing unit) and the like, and when the liquid crystal display start is instructed after the power is turned on, the common driver 16 and the segment driver 1 based on the system clock signal SCK input from the interface block 13.
As various timing control signals for controlling 7, the common control signal and the segment control signal are generated and output to the common driver 16 and the segment driver 17. The common driver 16 controls the sequential scanning timing of the scanning line for each field in one frame, and the segment driver 17 controls the sampling timing of the driving voltage of the signal line for each field in one frame.

The display control block 12 has various display functions of the LCD 18 based on various instructions (clear command, standby command, system set command, dot shift command, test mode command, etc.) input from the interface block 13. Initially set the related setting items, and set these initial setting items (setting items for the dot display character width and horizontal dot shift that are set for each display line).
Based on, the display control of the character to be displayed in multiple lines on the LCD 18 is executed.

The interface block 13 generates a system clock signal SCK necessary for LCD display control based on a basic clock signal input from a clock oscillation block (not shown) and outputs the system clock signal SCK to the display control block 12. Display serial code data input from a main control block (not shown) is level-converted and output to the display data memory block 14. Also,
The interface block 13 includes various instructions (clear instruction, standby instruction, system set instruction, dot shift instruction,
The test mode command, etc.) is level-converted and output to the display control block 12.

The display data memory block 14 is a character generator ROM (hereinafter referred to as CGROM) for storing character data such as symbols and characters, and a character generator RAM (hereinafter referred to as CGROM) to which a user can write arbitrary symbols and characters. CGRAM) or a display data RAM that has a storage area having the same configuration as the character display area of the LCD 18 and expands a predetermined memory address stored in the CGROM or CGRAM to the display position.
(Hereinafter referred to as DDRAM) and the like.

Therefore, the display data memory block 1
Reference numeral 4 expands the character data, which is memory-addressed by the serial code data input from the interface block 13, to the DDRAM at the specified memory address of the CGROM or CGRAM according to the display position specification of the serial code data. The corresponding display data is read from the CGROM or CGRAM from the memory address and output to the gradation control block 15.

Further, the display data memory block 14 is
In response to a memory control signal (data write command, display clear / reset command) input from the display control block 12, data expansion to the DDRAM and holding of the expanded data are performed, and at the same time, the expanded data is erased.

The data gradation control block 15 is a CGRO.
The parallel display data read from the M and CGRAMs is converted into serial data, and the grayscale data in which the pulse width of each liquid crystal drive pulse is set based on the serial display data is output to the LCD 18, and the grayscale of the LCD 18 is displayed. The display data is controlled, and the display data input from the display data memory block 14 is converted into gradation data according to the pulse width setting and output to the segment driver 17.

The common driver 16 sequentially scans and drives a predetermined number of scanning lines in the LCD 18 at the control timing of the common control signal input from the display control block 12, and the display ON input from the display control block 12 is turned on. The drive voltage level on the scanning line side is set to the "H" level (VCC by the ON / OFF control signal and the display clear / reset signal).
Level, when the display is ON) or "L" level (V
SS (ground) level, display OFF, display clear / reset).

The segment driver 17 sequentially selects a predetermined number of signal lines in the LCD 18 according to the control timing of the segment control signal input from the display control block 12, and the grayscale data input from the data grayscale control block 15 is selected. Are sequentially transferred to the selected signal line, and display ON / OFF input from the display control block 12 is input.
The drive voltage level on the signal line side is set to the “H” level (VCC level, by the OFF control signal and the display clear / reset signal).
Display ON) or "L" level (VSS (ground) level, display OFF, display clear / reset).

In the LCD 18, liquid crystal is sealed between a pair of transparent glass substrates, and a plurality of scanning lines and signal lines are formed in a matrix on the opposite surfaces of the pair of transparent glass substrates. Display dots made of liquid crystal are formed at the respective intersections with, and the scanning lines and the signal lines are selectively driven by the drive control by the common driver 16 and the segment driver 17, so that the grayscale data is sequentially displayed on the liquid crystal at the selected intersections. However, the electric charge is accumulated and a character or an image based on the display data is displayed.

Next, the operation of this embodiment will be described. First,
Various instructions used in the dot display character width control of the liquid crystal display device 1 of this embodiment will be described.

In the interface block 13 of the present embodiment, the following three types are mainly used as various instructions input from the main control block.

(1) Instructions (commands, registers) for setting LCD display functions such as display method and display function (2) Instructions for giving addresses of the DDRAM in the display data memory block 14 (address registers, address data) ( 3) Instruction for writing data to the DDRAM in the display data memory block 14 (data writing) In a normal use state, the instruction of (3) for sending the display data is most frequently used, and the instruction of (1) (command) , Register) is independent (1 unit: S
CK (system clock) x 8 units, 1 unit is input with an 8-bit code), but (2),
In each instruction (3) (address register, address data, data write), the operation is performed until an arbitrary RAM and register are selected, an arbitrary address is determined, and data is written, so at least 3 units (SCK ×
3 × 8) is required. The basic structure of these instruction instructions is shown in FIG.

The command (1) and the specific instruction instruction of the register are as follows. Clear command → Initialize each register and display OF
F Display ON / OFF control command → All display ON / O
Control FF. Standby command → Stop DC / DC converter and reduce power supply current. System set command → Set the number of display lines. Dot shift command-> Set horizontal dot shift for displayed characters. Test mode instruction → Set test mode.

When the display control block 12 is operated, it is necessary to execute the above-mentioned instruction instructions to initialize the display. The execution processes of these instruction instructions will be described with reference to specific examples of setting each code data corresponding to each instruction instruction.

For example, in order to display a 12-digit 4-line on the LCD 18, as shown in FIG. 3, the system set instruction (command register) of "0001110" is displayed.
The number of display digits of 12 columns and 4 lines is set by setting 0 ". In this 12 columns and 4 lines display, the character width (5 dots / 6 dots) of an arbitrary line is selected and the horizontal dot shift line is set. When designating, <Address register (AR)> and <Address (A
D)>, <Data (DTn)> in this order.

As concrete setting contents, first, the address register of the registers to be accessed by the address register instruction shown in FIG. 4 is selected. In this Figure 4,
Bits b5 to b3 are assigned to selection codes AD3 to AD1, and the dot shift selection register is selected by setting "11011000". FIG. 5 shows a code setting example in the case where the dot shift selection address data is written following this instruction. The setting example "00000000" specifies "00h" as the dot shift selection address data.

Next, as a "write dot shift data" command, FIG. 6 shows an example of code data setting for selecting the character width (5 dots / 6 dots) of an arbitrary line and designating a horizontal dot line. . In FIG. 6, bit b7
~ B4 are W4 to W1 codes for character width selection, and bit b
3 to b0 are L4 to L1 codes for dot shift designation.

The setting contents of the character width selecting W4 to W1 code and the dot shift specifying L4 to L1 code will be described with reference to the setting examples of the W register and the L register shown in FIG.

In the character width selection W4 to W1 codes, the line corresponding to each code number is set to have a width of 5 or 6 dots / character. As shown in the figure, the W4-W1 codes are
"0" sets the line to 5 dots wide / character, and "1" sets the line to 6 dots wide / character. Further, in the dot shift designation L4 to L1 codes, the line corresponding to each code number is horizontally dot shifted (smooth scroll mechanism).
Select whether to do. As shown in the figure,
In the L1 code, "0" sets the corresponding line without dot shift (smooth scroll), and "1" sets the corresponding line with dot shift (smooth scroll).

However, this time, "dot shift" means
Only the 6-dot width / character line is specified, and the line for which the 5-dot width / character is set is prohibited (see the setting prohibition section in FIG. 7).

For example, in the 12-digit 4-line display mode,
Set the 1st and 2nd lines to 6 dots width / character, set the 3rd and 4th lines to 5 dots width / character, and set the line without dot shift to 1
If the lines 3, 3, 4 and the line with dot shift are set as the second line, the code setting contents of the "write dot shift data" command shown in FIG. 6 are as shown in FIGS. As shown, it becomes "00110010". In other words, the first line has 6 dots width / character and no dot shift, the second line has 6 dots width / character dot shift, and the third line has
5 dots width / character, no dot shift, and the fourth line is a display with 5 dots width / character, no dot shift.

For example, the display data memory block 1
A memory area for storing display data corresponding to the display digit and the display row shown in FIG. 10 is formed in the DDRAM in FIG. 4, and the LCD is displayed based on the display data stored in this memory area.
When the character data is displayed on 18 in four columns of 12 digits, the display is as shown in FIG. 11, and the display character width (dot font width, 5 dots / 6 dots) of each line can be arbitrarily set by an instruction command.

Although the setting contents of the W register and the L register are shown in FIG. 7, the display is not limited to the above 12-digit 4-line display.
As shown in FIG. 2, by changing the code setting contents of the system set instruction, 12-digit 3-line, 12-digit 2-line,
By setting each display mode of 12 columns and one line, it is possible to specify the width of 5 dots or 6 dots / character line and the line to be dot shifted / not to be shifted in each display mode.

Further, in the above embodiment, the character width (5
Although the selection of dots or 6 dots and the designation of the horizontal dot shift line are set by two codes, by setting them within the same code (instruction instruction 8 bits) (set by a pair), the instruction It is also possible to reduce the number.

As described above, the liquid crystal display device 1 of this embodiment
Then, in the dot display character width control, the display character width of each line, 5 dots / character line, 6 dots / character line, and the line to be dot-shifted and the line not to be dot-shifted can be arbitrarily set by the same instruction instruction code setting. By making it possible, the LCD 18
Mixed display of dot width / character or 6 dot width / character and line with dot shift / line without dot shift is possible, and various character displays can be expressed, and the LCD display digit line for dot display can be used more effectively. can do. In the above embodiment, the case where the character width of each line can be arbitrarily set for the 12-digit N-row display has been described. However, even when the M-digit N-row display is driven, the M-digit N-row display is supported. By newly setting the same instruction code as described above, the above character display function can be realized.

(Second Embodiment) FIGS. 12 to 17 are views showing a second embodiment of a liquid crystal display device to which the present invention is applied.
The liquid crystal display device of the present embodiment has the same structure as the liquid crystal display device 10 shown in the first embodiment, and therefore the illustration and description thereof will be omitted.

In the first embodiment, the W register (W1 to W) is used as the "write dot shift data" command.
4) The character width of any line (5 dots or 6 dots) is selected by 4) and the horizontal register is set by the same instruction instruction that specifies whether or not the horizontal dot shift line is set by the L registers (L1 to L4). In the example, selection of the character width (p dot or q dot) of any line by the X register (X1 to X4) and designation of horizontal double-width display by the Y register (Y1 to Y4) are performed by the same instruction instruction. A case where each line is set arbitrarily will be described.

First, the instruction instruction (clear instruction, standby instruction, system set instruction,
The basic structure of the dot shift instruction, test mode instruction, etc.) is as shown in FIG. The execution process of these instruction instructions will be described below by showing a specific example of each code data setting corresponding to each instruction instruction.

As shown in FIG. 13, the code data structure of the system set instruction is as shown in FIG. 3 in the first embodiment.
It has the same configuration as. In addition, as for the code setting of the address register instruction, as shown in FIG. 14, the horizontal double angle display selection register is selected by the address register (AR). In FIG. 14, the bits b5 to b3 are assigned to the codes AD3 to AD1 for selection, and "1110,000" is assigned.
The horizontal double-width display selection register is selected by setting "0".

An example of code setting in the case of writing the address data for horizontal double-width display selection following this instruction is shown in FIG.
Shown in By inputting this setting example "00000000", access to the horizontal double-width display selection registers (X register and Y register) is confirmed.

Then, "writing of double-width display data"
Character width of any line as an instruction (p dot / q dot)
FIG. 16 shows an example of code data setting in the case of selecting and the setting data for displaying / not displaying horizontal double-width of an arbitrary line. In FIG. 6, bits b7 to b4 are X4 to X1 codes for arbitrary character width selection, and bits b3 to b0 are Y4 to Y1 codes for horizontal double-width display selection.

The setting contents of the character width selection X4 to X1 code and the horizontal double-width display selection Y4 to Y1 code will be described with reference to the setting examples of the X register and the Y register shown in FIG.

In the character width selecting X4 to X1 codes, the line corresponding to each code number is set to p or q dot width / character. As shown in the figure, the X4 to X1 codes are
"0" sets the line to p dot width / character, and "1" sets the line to q dot width / character. Further, in the Y4 to Y1 codes for horizontal double-width display selection, it is selected whether or not the line corresponding to each code number is displayed in double-width double-width. As shown in the figure, in the Y4 to Y1 codes, "0" sets the corresponding line to no horizontal double-width display (normal display), and "1" sets the corresponding line to horizontal double-width display.

For example, in the N-digit 4-line display mode, 1
Q dot width / character on the 3rd and 4th lines, p on the 3rd and 4th lines
Set the dot width / characters, set the rows that do not display double-width (normal display) as the first and fourth rows, and set the rows that display double-width to two.
When the line 3 and the line 3 are set, the code of the "write horizontal double width display data" command shown in FIG.
0110 "is set.

That is, the first line is a normal display with q dot width / character, and the second line is a double-width display with q dot width / character.
The second line is a double-width display with p dot width / characters, and the fourth line is p
The dot width / characters are displayed on the LCD 18 as a normal display. Therefore, by setting the display character width of each line (dot font width p dots / q dots) and the setting of double-width display of each line with the same instruction command, more diverse character display can be performed line by line. Can be displayed.

The character width of each line (p dot or q
If the selection of “dot” and the designation of horizontal double-width display can be set within the same code (8-bit instruction instruction), the number of instruction instructions can be reduced.

As described above, in the liquid crystal display device of the present embodiment, in the dot display character width control, the display character width of each line,
By setting the p dot / character line, q dot / character line setting, and the line for displaying double-width characters and the line for double-width character display by setting the same instruction command code, the p-dot width on the LCD 18 can be set. / Character or q dot width / Character and line with double-width display / Line without double-width display are possible, and various character display can be expressed, and the display digit line of LCD when dot display is used more effectively can do.

In the above embodiment, the case where the character width of each line for N-digit 4-line display and the display of double-width characters can be arbitrarily set has been described.
Even when the M-digit R-row display is driven, the same instruction code corresponding to the M-digit R-row display is newly set, so that the display of the first embodiment and the display of the second embodiment are mixedly displayed. It is also possible to let.

[0055]

According to the first aspect of the present invention, the display width of the display data is set for each display row in the liquid crystal panel, and it is possible to perform mixed display of rows that are horizontally shifted / lines that are not horizontally shifted. It is possible to express various characters and to more effectively use the display digit line of the liquid crystal panel when displaying dots.

According to the second aspect of the present invention, the display width of the display data is set for each display line in the liquid crystal panel, and it becomes possible to display the double-width display line / non-double-width display line mixed display, and various characters can be displayed. The display can be expressed, and the display digit line of the liquid crystal panel at the time of dot display can be used more effectively.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a liquid crystal display device of a first embodiment to which the present invention is applied.

FIG. 2 is a diagram showing a basic configuration of instructions used for display control of the LCD of the first embodiment.

FIG. 3 is a diagram showing a code data setting example of a system set command used for display control of the LCD of the first embodiment.

FIG. 4 is a diagram showing an example of setting code data of an address register used for display control of the LCD of the first embodiment.

FIG. 5 is a diagram showing a code data setting example of a dot shift selection address data write command used for display control of the LCD of the first embodiment.

FIG. 6 is a diagram showing code data setting contents of a dot shift data write command used for display control of the LCD of the first embodiment.

7 is a diagram showing an example of setting contents of a W register and an L register for setting the character width selecting W4 to W1 codes and the dot shift specifying L4 to L1 codes of FIG. 6;

8 is a diagram showing a specific example of code data set in the dot shift data write command of FIG.

9 is a diagram showing the setting contents of the code data of FIG.

10 is a diagram of D in the display data memory block 14 of FIG.
FIG. 6 is a diagram showing a configuration example of a display data storage memory area formed in a DRAM.

11 is a diagram showing a specific example of 12-digit 4-line display of characters displayed on the LCD based on the display data stored in the DDRAM of FIG.

FIG. 12 is a diagram showing a basic configuration of instructions used for display control of an LCD according to a second embodiment of the present invention.

FIG. 13 is a diagram showing an example of code data setting of a system set command used for display control of the LCD of the second embodiment.

FIG. 14 is a diagram showing a code data setting example of an address register used for display control of the LCD of the second embodiment.

FIG. 15 is a diagram showing an example of code data setting of a dot shift selection address data write command used for display control of the LCD of the second embodiment.

FIG. 16 is a diagram showing code data setting contents of a dot shift data write command used for display control of the LCD of the second embodiment.

17 is a diagram showing an example of setting contents of an X register and a Y register for setting the X4 to X1 code for character width selection and the Y4 to Y1 code for dot shift designation in FIG. 16;

[Explanation of symbols]

 10 display control unit 11 power supply block 12 display control block 13 interface block 14 display data memory block 15 data gradation control block 16 common driver 17 segment driver 18 LCD

Claims (2)

[Claims] 1. A liquid crystal driving method for displaying the liquid crystal panel based on display data and various instruction signals output from the control means, the control means driving and controlling a liquid crystal panel having at least a plurality of rows and a plurality of columns. By the control means, setting of a display line for displaying display data on the liquid crystal panel, setting of a display width of the display data on the display line, and presence / absence of horizontal shift of the display data on the display line are set. And displaying the display data on the liquid crystal panel based on the display width of the display data set in the display row and the presence / absence of horizontal shift. 2. A liquid crystal driving method for displaying the liquid crystal panel based on display data and various instruction signals output from the control means, the control means driving and controlling a liquid crystal panel having at least a plurality of rows and a plurality of columns. The control means sets the display line for displaying the display data on the liquid crystal panel, the display width of the display data on the display line, and the presence / absence of double-width display of the display data on the display line. A liquid crystal driving method, wherein display data is displayed on the liquid crystal panel based on the display width of the display data set in the display row and the presence / absence of double-width display.