JP2004294524A - Display driver, electrooptical device, electronic equipment, and driving and setting method of display driver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display driver which is used to automatically set screen information in a display section. <P>SOLUTION: A display driver 100 is provided with an EEPROM142 which stores screen information indicating driving locations of the pixels to be driven in an LCD150, a nonvolatile storage means, a ROM control circuit 140 which reads the screen information from the EEPROM142 in synchronism with power supply turn-on and a control circuit 112 which sets the driving locations for an LCD driving circuit 124 based on the read screen information. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a display drive device, an electro-optical device, an electronic device, and a drive setting method of a display drive device.
[0002]
[Prior art]
Conventionally, in an LCD (Liquid Crystal Display) driver, setting information for changing and setting a driving voltage such as an electronic volume value for adjusting contrast has been transferred from an external system including a microcomputer or the like.
On the other hand, in order to reduce the trouble of setting the setting information at the time of assembling the display device including the LCD driver, the setting information is stored in a nonvolatile storage unit in advance, and when the power is turned on, the setting information is automatically stored based on the setting information. An LCD driver that sets an electronic volume value in a computer has been proposed (for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. Hei 10-301081
[Problems to be solved by the invention]
On the other hand, for example, a buyer who has obtained an LCD driver provided by a supplier may use only a part of the display area in a display unit for display driving, for example. At the time of assembling the used display device, it is necessary to set other screen information such as the resolution of the display unit, the pixels to be driven, and the arrangement of sub-pixels (dots) constituting the pixels. Conventionally, these settings are performed by reading various commands from an external system into the LCD driver.
Further, in these settings, a situation in which the register in which the information is set is unexpectedly cleared due to an external factor such as ESD (Electro Static Discharge) may occur. Due to this situation, the LCD driver cannot perform normal display thereafter unless the screen information is reset in the cleared register.
[0005]
SUMMARY An advantage of some aspects of the invention is to provide a display driving device, an electro-optical device, an electronic device, and a driving setting method of a display driving device for automatically setting screen information on a display unit. It is in.
Still another object is to provide a display driving device, an electro-optical device, and an electronic device for suppressing a display abnormality caused by clearing set screen information.
[0006]
[Means for Solving the Problems]
(1) In order to solve the above-described problems, a display driving device according to the present invention stores driving means for driving a display unit in which pixels are formed, and screen information indicating a position of a pixel to be driven among the display units. Non-volatile storage means, reading means for reading screen information from the non-volatile storage means, and drive setting means for setting a position on the driving means based on the screen information read by the reading means It is characterized by.
This makes it possible to automatically set the screen information on the display unit, and to eliminate the complexity of the conventional screen adjustment.
[0007]
(2) Further, according to the present invention, in the display driving device according to the above (1), the readout unit may be configured so that the nonvolatile storage unit is synchronized with supply of a power supply voltage from a power supply circuit that supplies a voltage. Reading the screen information from the.
As described above, the screen information on the display unit is automatically set in synchronization with the supply of the power supply voltage, and the complicated screen adjustment in the related art can be eliminated.
[0008]
(3) Further, according to the present invention, in the display driving device described in (1) or (2), the reading unit reads screen information from the nonvolatile storage unit at predetermined intervals. .
As a result, the screen information can be updated at any time, and the period in which the set screen information is unexpectedly cleared due to an external factor such as ESD can be minimized.
[0009]
(4) Further, according to the present invention, in the display driving device according to any one of the above (1) to (3), display information is stored in the non-volatile storage means, and the reading means is The display information is read from the non-volatile storage means, and the driving means causes the display section to display the display information read by the reading means.
As described above, display information such as a lot number may be displayed in synchronization with the setting of the screen information.
[0010]
(5) Further, the present invention can be used as an electro-optical device including the display driving device according to any one of the above (1) to (4).
[0011]
(6) Further, the present invention can be used as an electronic apparatus including the electro-optical device according to the above (5).
[0012]
(7) In the drive setting method for a display driving device according to the present invention, the screen information is read out from a non-volatile storage unit that stores screen information indicating a position of a pixel to be driven in a display unit in which the pixel is formed. A position based on the set screen information, and driving the set position on the display unit.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0014]
<First embodiment>
The configuration of the display driving device according to the first embodiment will be described with reference to FIGS.
FIG. 1 shows a block diagram of a liquid crystal device 10 including a display driving device 100 according to the present embodiment.
The display drive device 100 supplies a drive voltage to the LCD 150 based on the voltage supplied from the voltage generation circuit 132 that boosts the power supply voltage. Y drive circuit 30 is a circuit that supplies a selection voltage to a scanning line (not shown) in LCD 150. X drive circuit 20 is a circuit that supplies a drive voltage to a data line (not shown) in LCD 150.
[0015]
The EEPROM 142 stores screen information in which a pixel position to be driven is set in a sub-pixel (dot) range formed on the LCD 150. For example, in the LCD 150 in which dots in RGB units are formed in order from the left end as shown in FIG. 3A, when the range z shown in FIG. 3B is not used (in this case, the unit of BRG is The screen information is set as information indicating a range excluding this range z.
[0016]
FIG. 2 shows a configuration of the display driving device 100.
The display driving device 100 includes a display data RAM (Random Access Memory) 122 functioning as a display frame memory.
[0017]
The control circuit 112 that has received the display data D indicating R (Red), G (Green), and B (Blue) transmitted from the input / output buffer circuit 110 transmits the display data D to the I / O buffer circuit 116.
[0018]
The ROM control circuit 140 reads out the screen information stored in the EEPROM 142 or writes the screen information in the EEPROM 142.
The ROM control circuit 140 accesses the EEPROM 142 and reads out the stored screen information in synchronization with the input of a reset signal from the outside and the start of the system of the display driving device 100. The ROM control circuit 140 accesses the EEPROM 142 every predetermined period, for example, every two times the frame frequency corresponding to the length of one vertical scanning period (1 V), and transmits the read screen information to the control circuit 112. .
[0019]
The control circuit 112 instructs the display data RAM 122 to perform a read (read) or write (write) operation based on a display command supplied from a command decoder (not shown).
Further, the control circuit 112 generates a control signal such as a clock signal CLK as a timing pulse, a horizontal synchronization signal Hsync, a vertical synchronization signal Vsync, and a grayscale control signal GCP (Grayscale Control Pulse) for performing PWM (pulse width modulation). I do. By supplying this control signal to the column address control circuit 118 and the page address control circuit 120, the counter stored in each of these circuits 118 and 120 is set or reset in accordance with the read or write operation. Is As a result, the display data D stored in the I / O buffer circuit 116 is sequentially written to the display data RAM 122.
[0020]
The control circuit 112 that has received the screen information specifies the write address of the display data RAM 122 to the column address control circuit 118 and the page address control circuit 120 based on the drive position indicated by the image information.
Here, as shown in FIG. 4, in the LCD 150 formed of 316 dots vertically and 1200 dots horizontally, 9 dots at both ends in the X direction and 8 dots each at both ends in the Y direction are not driven. A description will be given (that is, the driving is within the range 150A).
[0021]
The control circuit 112 specifies a write address of the display data RAM 122 for the column address control circuit 118 and the page address control circuit 120, and a memory element corresponding to the drive range 150A shown in FIG. Is written with the information of the display data D. The written display data D is read in the Y direction as one-line display data of “RGB × 394 (the number of pixels in the X direction) = 1182 dots”, and is supplied to the LCD 150 by the LCD driving circuit 124. Converted to voltage.
[0022]
Here, as shown in FIG. 3, when the arrangement of the dots changes, the BRG sub-pixels represent one unit of pixel when viewed from the left end. Therefore, the control circuit 112 includes the column address control circuit. It instructs the address 118 and the page address control circuit 120 to shift the write address of the RG display data among the RGB display data transmitted from the input buffer circuit 110 of the display data RAM 122. As a result, display driving with BRG as one unit of pixel is performed by the LCD 150.
[0023]
In addition, as shown in FIG. 5, the ROM control circuit 140 reads data mode conversion information described below from the EEPROM 142. The control circuit 112 receives display data D indicating R (Red), G (Green), and B (Blue) transmitted from the input / output buffer circuit 110 based on the conversion information. And a 4-bit data mode are mutually converted based on a conversion table in which conversion information is defined. At this time, the 4-bit display data "1010" is converted into 6-bit display data "101101" by the conversion table. Then, a driving voltage corresponding to the converted display data “101101” is supplied to the LCD 150.
This makes it possible to display low-resolution display data at high resolution.
[0024]
As described above, in synchronization with the power-on, the pixel to be driven in the LCD, or the screen information such as the arrangement and resolution of the dots constituting the pixel is automatically set. The complexity of screen adjustment appropriately performed by an external system or the like can be eliminated.
[0025]
(Other forms of display driving device)
In the display driving device 100 according to the first embodiment shown in FIG. 1, the ROM control circuit 140 uses the ROM control circuit 140 every predetermined period, for example, twice the frame frequency corresponding to the length of one vertical scanning period (1 V). The EEPROM 150 may be accessed for each of the periods, and the read screen information may be transmitted to the control circuit 112. Then, the control circuit 112 is caused to reset the screen information as described above. As a result, the screen information can be updated at any time, and the register of the control circuit 112, which has already been set to be written to the column address control circuit 118 and the page address control circuit 120, is reset by an external factor such as ESD. It is possible to minimize the period in which the settings are unexpectedly cleared.
[0026]
<Second embodiment>
Next, a display driving device according to the second embodiment will be described. In the display driving apparatus according to the present embodiment, in the display driving apparatus 100 of FIG. 2, unique lot number information capable of specifying the present apparatus is displayed and driven on the LCD 150 as display information. Lot number information is stored in advance in the EEPROM 142 of the display driving device according to the present embodiment. Hereinafter, the display driving device of this embodiment will be described with reference to FIG. 2 for convenience.
[0027]
In the display driving device of the present embodiment, the ROM control circuit 140 accesses the EEPROM 142 in synchronization with the input of a reset signal from the outside and the system of the display driving device 100 is started, and stores the stored lot number information. Is read. The ROM control circuit 140 transmits the read screen information to the control circuit 112. The control circuit 112 transmits the received lot number information to the I / O buffer circuit 116. Thus, the lot number information is written into the display data RAM 122. Then, the display is driven on the LCD 150 by the LCD drive circuit 124. FIG. 6 shows a case where, for example, “serial No. ABCD1234” is displayed on LCD 150 as lot number information.
[0028]
As a result, the screen information on the LCD is automatically set in synchronization with the power-on, and the lot number information, which was conventionally controlled by a command from an external system or a sticker, is simultaneously reset with the power-on. You will be able to confirm.
[0029]
<Various modes to which the present invention is applied>
Note that the display driving devices in the first and second embodiments described in the above embodiments are examples, and the present invention can take various forms without departing from the gist thereof.
For example, in the above-described other embodiment of the display driving device 100 in FIG. 2, a case where the register storing the screen information in the control circuit 112 is erased due to an external factor such as ESD has been described. Even when a reset command for transmitting a signal is generated due to these external factors and these registers of the display drive device 100 are reset unexpectedly, the period of display abnormality can be minimized.
[0030]
Further, as an example of the display driving device 100 shown in FIG. 2, a device including the display data RAM 122 has been described as an example. However, the present invention is not limited to this, and a display driving device without the display data RAM 122 may be applied. Can be.
[0031]
Also, in the above-described display drive circuit 100 shown in FIGS. 1 and 2, the description has been made assuming that the voltage generation circuit 132 and the EEPROM 142 are provided outside the drive control device 102 particularly in the portion related to the display drive (that is, 1 This is merely an example, and at least one of the voltage generation circuit 132 and the EEPROM 142 may be included in the drive control device 102 as one IC.
[0032]
In the display driving device of the second embodiment, the lot number information is displayed on the LCD 150 as an integrated device (IC) as the display information. In addition, for example, the voltage generation circuit 132 itself is a separate IC. If they are integrally formed, the lot number information of the voltage generation circuit 132 may be stored. This also applies to the LCD 150, the EEPROM 142, the LCD drive circuit 124, and the like.
In order to display the lot number information on the LCD 150, the lot number information is displayed on the LCD 150 via the display data RAM 122 as described above, and the LCD drive circuit is directly connected without the display data RAM 122. The data may be transferred to the display 124 for display output.
[0033]
<Electro-optical device and electronic equipment>
For example, as shown in the liquid crystal device 10 in FIG. 1, the liquid crystal device can be used as a liquid crystal device integrally including the display driving device in the above-described embodiment and various application forms thereof, and the LCD 150 as a display unit.
[0034]
FIG. 7 is an external view of a mobile phone 200 on which the liquid crystal device 10 is mounted. In this figure, the mobile phone 200 includes a liquid crystal device 10 as a display unit for displaying various information such as a telephone number, in addition to a plurality of operation buttons 210, an earpiece 220 and a mouthpiece 230.
In addition to the mobile phone 200, the liquid crystal device 10 including the display driving device of the present invention includes a computer, a projector, a digital camera, a movie camera, a PDA (Personal Digital Assistant), an in-vehicle device, a copying machine, an audio device, and the like. Can be used for various electronic devices. Further, the display driving device of the present invention can be applied not only to a liquid crystal device but also to an electro-optical device such as an EL (electro luminescence), a plasma display, an electrophoretic device (EPD), and an electron emitting device (FED). it can.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a liquid crystal device including a display driving device according to the present invention.
FIG. 2 is a block diagram of a display driving device according to the first embodiment.
FIG. 3 is a diagram for explaining an arrangement of dots in the device.
FIG. 4 is a diagram illustrating a range driven by the apparatus.
FIG. 5 is a diagram for explaining a conversion process of resolution information in the same device.
FIG. 6 is a diagram illustrating lot number information output by a display driving device according to a second embodiment.
FIG. 7 is a diagram illustrating an electronic apparatus including the liquid crystal device according to the first embodiment.
[Explanation of symbols]
Reference Signs List 10: liquid crystal device, 100: display driving device, 110: input / output buffer circuit, 112: control circuit, 116: I / O buffer circuit, 118: column address control circuit, 120: page address control circuit, 122: display data RAM , 124 ... LCD drive circuit, 132 ... voltage generation circuit, 140 ... ROM control circuit, 142 ... EEPROM, 150 ... LCD, 200 ... mobile phone.

Claims (7)

Driving means for driving a display unit in which pixels are formed;
A nonvolatile storage unit that stores screen information indicating a position of a pixel to be driven in the display unit;
Reading means for reading screen information from the nonvolatile storage means;
A display drive device comprising: a drive setting unit that sets a position based on the screen information read by the reading unit with respect to the driving unit. The display driving device according to claim 1,
The display driving device, wherein the reading means reads screen information from the nonvolatile storage means in synchronization with a supply of a power supply voltage from a power supply circuit for supplying a voltage. The display driving device according to claim 1 or 2,
The display driving device, wherein the reading means reads screen information from the nonvolatile storage means at predetermined intervals. The display driving device according to any one of claims 1 to 3,
Display information is stored in the nonvolatile storage means,
The reading means reads display information from the nonvolatile storage means,
The display driving device, wherein the driving unit causes the display unit to display the display information read by the reading unit. An electro-optical device comprising the display driving device according to claim 1. An electronic apparatus comprising the electro-optical device according to claim 5. Of the display unit in which the pixels are formed, the screen information is read from the non-volatile storage unit that stores the screen information indicating the position of the pixel to be driven;
Set the position based on the read screen information,
A drive setting method for a display driving device, comprising driving the set position on the display unit.

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