JPH096294A - Liquid crystal display device - Google Patents

Abstract

PURPOSE: To provide a liquid crystal display device in which a plurality of memory areas in which a display address corresponding to the display position of a liquid crystal panel is shifted one by one dot are developed within a DDRAM, and characters are scroll-displayed by shifting one by one dot. CONSTITUTION: In scroll display processing, when character data stored in a CGROM 52 and a CGRAM 53 are read, based on a control signal produced by a control circuit 32 based on execution instruction data, while referring to a plurality of memory areas which set display addresses corresponding to display position of a liquid crystal panel 2 equivalent to one line by shifting one by one dot in a DDRAM 51 character data whose read out is instructed, are sequentially sent to the CGRAM 53 and developed, grouped for every one line constituting character data developed, and read as parallel data, outputted to a driving means 60. Scroll-display of characters which is shifted one by one dot is conducted in the liquid crystal panel 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device,
More specifically, the present invention relates to a liquid crystal display device having a scroll display function for display data.

[0002]

2. Description of the Related Art Recently, ROM (Read Only Memory), RAM (Random Access Memory), etc. for storing character data and display data of a fixed size specified in advance have been realized in order to realize a compact and high-speed liquid crystal display device. The memory has been integrally formed as a module with a liquid crystal drive circuit.

As a conventional liquid crystal display device in which such a memory and a driving circuit are modularized together with a liquid crystal display panel, an interface circuit, a decoder, a control circuit, a D
DRAM (display data RAM), CGRA
M (character generator RAM), CGROM
It is equipped with a (character generator ROM), a data conversion circuit, a liquid crystal drive circuit, and the like. This liquid crystal display device is incorporated in a small electronic device such as a mobile phone to display characters, symbols, and the like.

The DDRAM forms a display-addressed memory area necessary for displaying characters for one screen of a liquid crystal display panel. For example, when the liquid crystal display panel has a screen configuration of 9 digits × 1 line display and the displayed character font is 5 × 7 dots, the relationship between the DDRAM address, the display position of the liquid crystal display panel, and the segment wiring is as follows.
As shown in FIG. 7, one DDRAM address “00-08” is provided at a display position determined for each 5 × 7 dot display area.
Are set correspondingly, and S1 to S5, S6 to S10, S11 to S15, ... S in each 5 × 7 dot display area.
As in 41 to S45, a set of five segment electrodes is wired.

In the liquid crystal display panel as shown in FIG. 7, one DDRAM address "00-08" is set in correspondence with the display position determined for each 5 × 7 dot display area. When scrolling the characters, as shown in FIGS. 8A to 8C, the characters are scrolled from the left to the right and displayed one by one.

[0006]

However, in the liquid crystal display device incorporated in such a conventional small electronic device, one DDRAM address "00" is provided at the display position determined for each 5 × 7 dot display area. ~ 08 "is set correspondingly, and when displaying characters by scrolling, the characters are scrolled one by one from left to right, so the scroll display is not smooth and difficult to see. was there.

An object of the present invention is to develop a plurality of memory areas in the DRAM which are set by shifting the display address corresponding to the display position of the liquid crystal display panel by 1 dot, and shift the characters by 1 dot for scroll display. It is to provide a display device.

[0008]

According to another aspect of the present invention, there is provided a liquid crystal display device which displays various display data by turning on or off a plurality of predetermined pixels. A memory for storing the various display data in advance, a development memory for storing the display data at a display address corresponding to a display position of the liquid crystal display panel, and a display memory for reading the display data stored in the memory. Refer to the display address of
In the liquid crystal display device including a liquid crystal driving unit that displays the read display data at a corresponding display position of the liquid crystal display panel based on the display address, the expansion memory shifts by a predetermined dot and the display is changed. A plurality of display addresses for displaying data, the liquid crystal driving means refers to a display address corresponding to the expansion memory, and displays the display data read from the memory on the basis of each display address. The liquid crystal display panel is characterized in that it is scrolled by shifting to a corresponding display position by a predetermined dot.

Further, as in the liquid crystal display device according to the second aspect of the present invention, a plurality of display addresses included in the expansion memory are set such that the display data are shifted by one dot so that the respective display positions overlap. It is effective that the liquid crystal driving means shifts the plurality of display data to the corresponding display position of the liquid crystal display panel by one dot while referring to each display address of the expansion memory and scroll-displays.

Further, as in the liquid crystal display device according to the third aspect of the present invention, the liquid crystal drive means drives the display data on the liquid crystal panel for a predetermined time while referring to the display address of the expansion memory, It is effective to perform non-display driving of the display data for a predetermined time, then shift the display data by a predetermined dot, and drive the display data again for scroll display.

[0011]

According to the liquid crystal display device of the invention described in claim 1,
A liquid crystal panel that displays various display data by lighting or non-lighting a plurality of predetermined pixels, at least a memory that stores the various display data in advance, and a display position of the liquid crystal display panel. A development memory that stores the display data at a corresponding display address and the display data stored in the memory are read, the display address of the development memory is referred to, and the read display data is read based on the display address. In a liquid crystal display device comprising a liquid crystal driving means for displaying at a corresponding display position of a liquid crystal display panel, the expansion memory is provided with a plurality of display addresses for displaying the display data by shifting a predetermined dot. In the liquid crystal driving means, the display address corresponding to the expansion memory is referred to and the memory is Display data read from is scrolled by a predetermined dot at a time shifted display position corresponding to the liquid crystal display panel based on the respective display address. Therefore, the character data can be scrolled and displayed on the liquid crystal panel sequentially by a predetermined dot based on the display address, and a smooth scroll display of characters can be realized.

According to the liquid crystal display device of the second aspect of the present invention, the plurality of display addresses of the expansion memory are set so that the display data are shifted by one dot and the respective display positions are overlapped with each other. The drive means refers to each display address of the expansion memory and sets the plurality of display data to the corresponding display position of the liquid crystal display panel.
Scrolling is displayed with shifting by dots.

According to the liquid crystal display device of the third aspect of the invention, the liquid crystal drive means refers to the display address of the expansion memory to display-drive the display data on the liquid crystal panel for a predetermined time and then a predetermined time. The display data is driven for non-display for a time, then is shifted by a predetermined dot, and the display data is driven again for scroll display.
Therefore, the scroll display processing of the liquid crystal display device can be speeded up, and the scroll display of characters can be made smoother.

[0014]

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 6 are views showing an 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 an overall configuration of a liquid crystal display device 1 of the present embodiment. The liquid crystal display device 1 is composed of a liquid crystal panel 2 and a liquid crystal drive device 3, and a liquid crystal drive device 3 is provided.
A reference voltage and execution instruction data are input to the external controller 4 from the external controller 4.

FIG. 2 is a block diagram showing the internal structure of the liquid crystal drive device 3. The liquid crystal drive device 3 includes a control means 30 including an interface 31 and a control circuit 32,
It comprises a power supply unit 40, a memory unit 50 having a DDRAM 51, a CGROM 52 and a CGRAM 53, and a driving unit 60 having a parallel / serial data conversion circuit 61, a segment driver 62 and a common driver 63.

The interface 31 of the control means 30 is
The voltage levels of various execution instruction data input from the controller 4 are converted into predetermined values and output to the control circuit 32, and the reference voltage input from the controller 4 is output to the power supply means 40. The control circuit 32, based on various execution command data input from the interface 31,
The display execution command signal, the memory address designation of the memory section 50, and the decoding function for sorting and sorting the character data are provided, and various control signals are generated by this decoding.

Of the generated control signals, the memory section 5
The control signal output to 0 is DDRAM51, CGRO
Memory designation, display address designation, memory address designation, and write / read processing designation are performed for each memory of the M52 and CGRAM53. Specifically, CGR
Processing for selecting and reading character data at a predetermined memory address from various character data stored in the OM 52, CGR
When writing a character pattern to a predetermined memory address of the AM 53, a process of converting the character data input by serial data into parallel data and writing the parallel data in the CGRAM 53 is performed.

The control signals output to the segment driver 62 and the common driver 63 of the driving means 60 are a plurality of types of drive control signals for driving the liquid crystal panel 2, and are a synchronizing signal, a shift clock signal, and a scan. There are a start signal, a polarity inversion signal, a latch output signal, a data sampling signal, and the like.

In the DDRAM 51 of the memory section 50, the predetermined memory addresses of the designated CGROM 52 and CGRAM 53 are set on the basis of the display address at which the liquid crystal panel 2 displays characters and the memory address designated by the execution command data. Is a memory for writing / reading to / from a display address corresponding to the display location of, and has a memory capacity of a character row × B character string × n bits corresponding to the display screen configuration of the liquid crystal panel 2.

Further, the DDRAM 51 stores a plurality of memory areas in which display addresses for shifting display data by one dot are expanded as memory areas used in a character scroll display process described later.
The CGROM 52 is a memory for reading specified character data from various character data stored in advance by a control signal generated by the control circuit 32 based on the execution command data, and has a memory capacity of C character number × n bits. Have.

The CGRAM 53 writes the character pattern of the specified character data to the specified memory address by the control signal generated by the control circuit 32 based on the execution command data, and further reads and specifies the memory address. It is a memory that can read the written character pattern by d number of characters x
It has a memory capacity of n bits.

FIG. 3 is a diagram showing the correspondence between the character code stored in the CGROM 52 and the character pattern written in the CGRAM 53. The character code of this FIG. 3 is CGRO
The memory address in M52 is specified, and one memory address is represented by a character code of 1 character = upper 4 bits + lower 4 bits. In the storage area of the CGROM 52, the character codes “00000001” to “11
This is a read-only memory that is assigned up to 111111 ″, stores the character data of the number of character codes, and reads the character data designated by the control signal input from the control circuit 32.

For example, "00010000" is CGR
It is a memory address corresponding to the “A” character data stored in the OM 52.

The storage area of the CGRAM 53 is "0000".
0000 "to" 00001111 "are allocated, and this is a memory capable of writing and reading a character pattern of (N) characters.
The dot composition of one character stored in the GRAM 53 is 5 horizontal.
If it is represented by dots × 7 dots vertically, CGRO
A character pattern of 35 dots per character is stored in each memory address of M52 and CGRAM53.

As described above, when the predetermined character pattern is written in the predetermined memory address of the CGRAM 53, it is converted by the control circuit 32 based on the execution instruction data,
35 bits of one character are written as parallel character data. When reading the character data written in the CGROM 52 and the CGRAM 53, a read instruction is issued while referring to the display address stored in the DDRAM 51 based on the control signal generated by the control circuit 32 based on the execution instruction data. Memory addresses sequentially,
Group by 1 line for each character data,
It is read out as parallel data and output to the driving means 60.

When reading character data written in the CGROM 52 and the CGRAM 53 in the scroll display processing described later, based on the control signal generated by the control circuit 32 based on the execution command data,
While referring to a plurality of memory areas in which the display address corresponding to the display position of the liquid crystal panel 2 for one line is shifted by one dot in the DDRAM 51, the read-instructed character data is repeatedly expanded in the CGRAM 53, The expanded character data is grouped for each line constituting one line, read out as parallel data and output to the driving means 60, thereby causing the liquid crystal panel 2 to perform scroll display of characters shifted by one dot.

The driving means 60 comprises a parallel / serial data conversion circuit 61, a segment driver 62 and a common driver 63. The parallel / serial data conversion circuit 61 includes a CGROM 52 or a CGR.
The parallel character data output from the AM 53 is converted into serial data and output to the segment driver 62 in units of one common line of the liquid crystal panel 2.

Although not shown, the segment driver 62 includes a shift register corresponding to a segment line of the liquid crystal panel 2, a latch circuit for latching data in the shift register, and a plurality of shift drivers according to selection / non-selection of a display state. And a multiplexer that outputs a segment signal to the liquid crystal panel 2 while selecting a drive voltage. The segment driver 62 is driven by a display control signal input from the control circuit 32, a plurality of drive voltages supplied from the power supply unit 40, and serial data input from the parallel / serial data conversion circuit 61. A signal is generated and a segment signal is output to each segment line of the liquid crystal panel 2 in synchronization with a common signal described later.

Although not shown, the common driver 63 selects a plurality of drive voltages according to selection / non-selection of a shift register corresponding to a common line of the liquid crystal panel 2 and a common line for line-sequential driving, and the liquid crystal panel 2 And a multiplexer that outputs a common signal to. The common driver 63 sequentially drives and outputs the generated common signal to the common line of the liquid crystal panel 2 by the display control signal input from the control circuit 32 and the plurality of drive voltages supplied from the power supply means 40.

The power supply means 40 has a booster circuit (not shown) for boosting the reference voltage input from the interface 31 by a factor of 4, and a plurality of liquid crystal drive voltages (V0, V1, V2, V3) from the boosted voltage. V4) and a liquid crystal voltage generation circuit (not shown).

Next, the operation of this embodiment will be described. The operation when the scroll display of characters is performed in the liquid crystal display device 1 of the present embodiment will be described. First, in the display screen configuration of the liquid crystal panel 2, scroll display of characters will be described in the case where a character composed of horizontal 5 dots × longitudinal 7 dots = 35 dots is displayed for 8 characters as described above. From the display address "00" set in the memory area in the DDRAM 51, any character, for example, "A"
When scrolling is displayed on the display screen of the liquid crystal panel 2 from left to right, the execution command data relating to the scroll display from the controller 4 is input to the interface 31 of the control means 30 to start the character scroll display processing. To be done.

In the control circuit 32, the interface 31
CGRAM for writing the character data A and the memory address designation of the CGROM 52 for reading the character data A based on the execution command data related to the scroll display input from
The 53 memory addressing is decoded and each memory addressing is output to the memory section 50.

In the memory section 50, the character data A of horizontal 5 dots × vertical 7 dots configuration is read from the specified memory address of the CGROM 52 and written to the specified memory address of the CGRAM 53, and then the DDRAM 51 shown in FIG. The display address for one line stored in each memory area is referred to, and the display data for scroll-displaying the character data A of the memory addresses of the CGROM 52 and the CGRAM 53 for which reading is instructed are grouped for each line. The parallel data for each line corresponding to each display address is sequentially generated, and the generated parallel data is read and sequentially output to the parallel / serial data conversion circuit 61 in the driving unit 60.

Then, in the parallel / serial data conversion circuit 61, the parallel data for each line corresponding to each display address of the character A sequentially input from the memory section 50 is sequentially converted into serial data, and the liquid crystal panel 2 is displayed.
Are sequentially output to the segment driver 62 in units of one common line. Further, from the control circuit 32, the liquid crystal panel 2
A drive control signal (a synchronizing signal, a shift clock signal, a scan start signal, a polarity inversion signal, a latch output signal, a data sampling signal, etc.) for scroll-displaying the character A is displayed on the segment driver 62 and the common driver 63 of the driving means 60. Is output.

In the segment driver 62, the control circuit 3
A grayscale drive signal is generated by the display control signal input from the device 2, the plurality of drive voltages supplied from the power supply means 40, and the character A serial data input from the parallel / serial data conversion circuit 61. A segment signal is output to each segment line of the liquid crystal panel 2 in synchronization with a common signal described later. Further, in the common driver 63, the common signal generated by the display control signal input from the control circuit 32 and the plurality of drive voltages supplied from the power supply means 40 is sequentially driven and output to the common line of the liquid crystal panel 2. It

As a result of the scroll display operation of the control circuit 32, the memory section 50, the parallel / serial data conversion circuit 61, the segment driver 62 and the common driver 63, as shown in FIGS.
Display address 0 that is set to 1 and is shifted by 1 dot
According to 0 to 02, the letter A is scroll-displayed from left to right on the display screen of the liquid crystal panel 2. However, in the case of this scroll display, when the character A is shifted dot by dot based on the display address of each memory area stored in the DDRAM 51, the character display of the current DDRAM 51 is temporarily erased (all display is turned off. ) Is supposed to do.

First, in FIG. 4A, the character A is DDRA.
It is displayed based on the display address "00" set in the first memory area in M51, and once it is erased in the same figure (b), it is set in the next memory area in the DDRAM 51 in the same figure (c). 1 dot is shifted based on the displayed display address "01"
After being erased again in the same figure (d), in the same figure (e), DD
Based on the display address “02” shifted by one dot set in the next memory area in the RAM 51,
The figure shows a state in which one dot is shifted and scroll display is performed.

As described above, a plurality of memory areas are set in the DDRAM 51, each of which has a display address set to be shifted by one dot, and the character data is sequentially displayed on the liquid crystal panel 2 by one dot so as to be scroll-displayed based on the display address. It is possible to realize smooth scroll display of characters.

Further, the display address is set so as to be overlapped with the position shifted by one dot in the DDRAM 51, and, for example, as shown in FIGS. 5A to 5F, “01” is set for “00”. , "02", "03", "04", "0"
5 "is set so that the memory area of the DDRAM 51 for displaying characters can be arbitrarily selected.

Here, the display addresses "00", "01", "02", "03", "04" of each memory area,
"05" is the letter A, display address is "06", "07",
"08", "09", "0A", and "0B" have a letter B, display addresses "0C", "0D", "0E", "0F",
By writing the letter C in "10" and "11"
As shown in (a) to (f), the characters ABC can be scrolled on the liquid crystal panel 2 by shifting them by one dot.

Therefore, by arbitrarily selecting the display address set so as to be overlapped with the position shifted by one dot in the DDRAM 51 and scrolling the characters, the trouble of the erasing operation can be omitted, and the scrolling display process can be performed. Can be speeded up, and the scroll display of characters can be made smoother.

[0042]

According to the liquid crystal display device of the first aspect of the invention, the character data can be sequentially scrolled by one dot on the liquid crystal panel on the basis of the display address, and can be scroll-displayed. Can be realized.

According to the liquid crystal display device of the second and third aspects, the scroll display process of the liquid crystal display device can be speeded up, and the scroll display of characters can be made smoother.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a liquid crystal display device 1 to which the present invention is applied.

FIG. 2 is a diagram showing an internal configuration of a liquid crystal driving device 3 of FIG.

3 is a diagram showing a correspondence between a character code stored in a CGROM 52 and a character pattern written in a CGRAM 53 shown in FIG.

FIG. 4 is a diagram showing a case where a character A is scroll-displayed by a display address set in a DDRAM 51 shown in FIG.

FIG. 5 is a diagram showing another example of display addresses set in each memory area in a line unit in the DDRAM 51.

FIG. 6 is a diagram showing an example in which a character ABC is scroll-displayed by setting a display address of the DDRAM 51 of FIG.

FIG. 7 is a diagram showing a relationship between a conventional DDRAM address, a display position of a liquid crystal display panel, and segment wiring.

FIG. 8 is a diagram showing a conventional character scroll display state.

[Explanation of symbols]

 1 Liquid Crystal Display Device 2 Liquid Crystal Panel 3 Liquid Crystal Driving Device 4 Controller 30 Control Means 31 Interface 32 Control Circuit 40 Power Supply Means 50 Memory Unit 51 DDRAM 52 CGROM 53 CGRAM 60 Drive Means 61 Parallel / Serial Data Conversion Circuit 62 Segment Driver 63 Common Driver

Claims (3)

[Claims] 1. A liquid crystal panel for displaying various display data by lighting or non-lighting a plurality of predetermined pixels, at least a memory for storing the various display data in advance, and the liquid crystal display. A development memory that stores the display data at a display address corresponding to the display position of the panel, and the display data stored in the memory is read, and the read display data is displayed by referring to the display address of the development memory. A liquid crystal driving device for displaying at a corresponding display position of the liquid crystal display panel based on an address; and the display memory for displaying the display data by shifting the expansion memory by a predetermined dot. A plurality of addresses, the liquid crystal driving means refers to a display address corresponding to the expansion memory, The display data read from the serial memory, a liquid crystal display device, characterized in that the scroll display by a predetermined dot at a time shifted display position corresponding to the liquid crystal display panel based on the respective display address. 2. A plurality of display addresses included in the expansion memory are set such that the display data is shifted by one dot so that respective display positions overlap, and the liquid crystal driving means sets the display addresses of the expansion memory. 2. The liquid crystal display device according to claim 1, wherein the plurality of pieces of display data are scroll-displayed by shifting one dot by one dot to a corresponding display position on the liquid crystal display panel while referring to the display data. 3. The liquid crystal driving means drives the display data to be displayed on the liquid crystal panel for a predetermined time while referring to the display address of the expansion memory, then non-display-drives the display data for a predetermined time, and then to a predetermined dot. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is shifted by a minute and the display data is driven to be displayed again for scroll display.