JP3133414B2 - Color LCD display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color liquid crystal display system for realizing a color liquid crystal display device using, for example, an active matrix or a ferroelectric black and white display transmission type liquid crystal panel having a function of retaining image data. is there.

[0002]

2. Description of the Related Art Conventionally, in a color transmission type liquid crystal display device, column lines (called source lines or data lines) and row lines (called gate lines) are arranged in a two-dimensional matrix in a liquid crystal panel. A row line is sequentially selected by a gate line driving circuit arranged around the panel, and R and R are selected by a source line driving circuit arranged around the panel in synchronization with the row line selection.
The R, G, B color image display data is transferred to the pixel electrodes having the G, B color filters through the respective column lines. The row line selection and the source line drive are repeated as a unit of operation over all the row lines in the liquid crystal panel, and color display is performed by constantly turning on a white light source from the back of the panel.

A pixel electrode having a color filter is arranged in a vertical stripe pixel array in which vertically long pixel electrodes of three primary colors are arranged in a horizontal direction, and a delta pixel in which pixel electrodes of three primary colors are arranged at a vertex of a triangle. There are various arrays such as arrays.

[0004] In these color pixel arrays, one line is provided per color pixel.
Although it is a book, three column lines are required for three colors. In the delta pixel arrangement, 1.5 column lines and two row lines are required by sharing with adjacent pixels. Further, a color filter with fine processing is required.

On the other hand, in a black-and-white display transmissive liquid crystal panel, a color filter requiring fine processing for pixels is not required, and one column line and one row line are provided for one monochrome pixel. And the number of drive circuits for driving these may be reduced.

[0006]

In a color transmission type liquid crystal panel, the number of pixels, the number of wirings and the number of driving circuits for driving the pixels in the liquid crystal panel are larger than those of a black and white display transmission type liquid crystal panel. Above, an RGB color filter was required for RGB color pixels, and the panel structure was complicated, which also affected the manufacturing yield. Further, each of the RGB colors constituting one color pixel is arranged at a different position on the panel. For example, when only the R color is displayed, the other G and B pixels are blocked from light. The light transmission area is about 1/3 of the total pixel area, and there is a problem that the color saturation is reduced.

As a method for solving these problems, RG
Using a monochrome display transmissive liquid crystal panel having monochrome pixels corresponding to the area of the B color pixels, one color image display data is selected in time order from the RGB color image display data, and the monochrome display transmissive liquid crystal is selected. It has been considered that a color liquid crystal display is performed by sending an image to a panel and displaying an image, and controlling the lighting of a color light source corresponding to the display data in this time order.

However, regarding the relationship between the transfer of the color image display data to the liquid crystal panel and the lighting of the color light source, it is considered that the color light source is turned on after the transfer of the color image display data. There is a problem that the display is short and the display becomes dark. Furthermore, in order to brighten the display, it is considered that the transfer of color image display data is made faster and the lighting time of the color light source is made as long as possible. However, in order to make the display faster, a liquid crystal material (molecule) is used. There are many restrictions such as the operating speed of the device and the driving circuit speed.

When the color light source is turned on while transferring the image display data to the liquid crystal panel, the image display data of the color which has been transferred immediately before and is already displayed on the liquid crystal panel has not been completely rewritten. There is a problem that the displayed portion does not match the color of the currently lit light source according to the color image display data, and an image of the expected color cannot be displayed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to realize a color liquid crystal display by a monochrome transmissive liquid crystal panel having a simple panel structure. In addition, using a black and white display transmissive liquid crystal panel,
To provide a color liquid crystal display system that realizes color display faithful to data by matching the display image of the color image display data with the color of the light source to be turned on without significantly reducing the lighting time of the color light source. is there.

[0011]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and achieves the object by operating the image display data to be displayed in color in a light transmitting state when displayed on a monochrome display transmissive liquid crystal panel. Mode (normally black mode)
Using a liquid crystal panel, liquid Ri sent to the LCD panel by selecting one frame at a time color image display data for multiple several colors chronologically
Rewrite crystal panel entire Rutoki, I each send a black data of one frame between each color image display data selected one
The entire liquid crystal panel is rewritten with black data, and a color light source of a corresponding color is turned on in accordance with display of each color image display data and black data .

[0012]

According to the color liquid crystal display system of the present invention, a black-and-white display transmissive liquid crystal panel and a plurality of color image display data are stored in one color.
A circuit part that selects and sends time-divisionally to the LCD panel, a color light source that corresponds to the color of multiple color image display data, and a color light source that lights in synchronization with the transmission of this color image display data to the LCD panel A liquid crystal display device is configured from a control circuit unit and a display image of the color image display data and a light source to be lit by controlling transmission of the image display data of a plurality of colors to the panel and lighting of the color light source as follows. And display a faithful color image.

[0013]

[0014] That is, in the present invention, writing the liquid crystal panel entire surface Ri feed select color image display data for one frame from the image display data in a plurality of colors to black and white display transmission type liquid crystal panel
You can place Rutoki, 1 frame between each color image display data
The data of the previous color is completely erased from the liquid crystal panel display by the black data. This allows
When the next color data is sent, the LCD panel is in a light-blocking state, and by turning on the color light source of the corresponding color when transferring and displaying each color image display data and black data to the LCD panel. The color light source and the displayed color image display data match, and a color image of a faithful color is displayed.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. As an embodiment of the color liquid crystal display system according to the present invention, color image display data of a plurality of colors is represented by R, G, and B colors.
The following describes an example in which color image display data of a color is selected, and these data are selected in order and sent to the liquid crystal display panel. In each of the drawings, a negative logic signal is indicated by a bar above the reference numeral, but in the following description, a minus sign is added before the reference numeral.

First, prior to the embodiment of the present invention, the present invention
Each color image instead of one frame of black data for comparison with
A reference example in which one frame of image data is transmitted will be described. Figure 1 shows R, G, and relationship to light the color light sources corresponding to the color of the state and the color image display data displayed on the liquid crystal panel B color image display data in this embodiment. 1 a liquid crystal display panel (hereinafter also simply referred to as panel or liquid crystal panel) indicates, -VS vertical synchronizing signal, t ₀ ~t ₆
Indicates the time between them, and RL, GL, and BL indicate the respective color light sources.

The lighting of the transfer and color light sources of a color image display data in the present embodiment is performed as follows. Time t ₀ immediately before the time the color image display data of the B color which has been displayed on up to t ₀
Over a time t ₁ from the rewritten by the color image display data of R color. During this time, since the images of the color image display data of the R color and the B color are mixed, the R light source R
L without lighting the, again, from time t ₁ to time t ₂ and sends the color image display data of the same color R to the panel 1, to turn on the R color light source RL when displaying it. Subsequently, although the display by sending the same G color color image display data between times t ₂ time t ₃ and time t ₃ time t ₄ from the panel 1, the lighting of the G-color light source GL is time t ₃ performed between the time t ₄ from. In addition, the time from the time t ₄ t ₅ and time t ₅
Displaying sends the same B-color color image display data of the panel 1 between times t ₆ from, but the lighting of the B-color light source BL is performed between time t ₅ the time t _6. The above operation is repeated.

FIG. 2 shows a reference example of a control circuit configuration of the color image display data and the color light source at this time, and FIG. 3 shows a timing chart thereof. 1 is a liquid crystal display panel, 2 is a source line driver (S • DR), 3 is a gate line driver (G • D).
DR), 4 color light source lighting control unit (LCONT), 5 is a frame memory (M _Rf ~M _Br), 6 is a timing controller for generating various timing signals (CONT). The timing controller 6, R externally, G, B of color image display data _{(R D, G D, B} D) 7 1, 7 2, 7 3 and vertical, horizontal synchronizing signal (-VS, - HS) to enter the 8 _1, 8 _2. Reference numeral 9 denotes a switch (SW) for selecting the image display data read from the frame memory 5. When the image display data is digital data, a logical AND (AND) output with the color selection control signals A, B, and C is ORed ( OR), and when the input data of the source line driver 2 is analog data, the AC conversion circuit (ALT) 10 also performs analog conversion. 11 is a decoder (DEC).

The timing waveforms of the color selection control unit signals A, B, and C are the waveforms shown in FIG.
Decoder 1 for receiving the LC signal triple speed of the S) 8 ₁
1 is a signal which is the basis of selection of color image display data and lighting control of a color light source. The frame memory 5 has both front and rear sides.
If one is a write, the other is in a read state. Symbols r and f shown in FIGS. 2 and 3 indicate the front and back of the frame memory. Writing to the frame memory 5 is performed by the write enable signals -r _WE , -f _WE for R, G,
B of color image display data R _D of, G _D, parallel write B _D, the read enable signal -r _RE1 ~-r _RE3 used for reading from the frame memory 5, -f _RE1 ~-f _RE3
As a result, the NAND output of the color selection control signals A, B, and C, the front / back selection signal -f / r for selecting the front and back of the frame memory 5, or this NOT signal is used. The read clock RC uses a clock that is six times faster than the write clock WC. As described with reference to FIG. 1, in order to successively display twice on the liquid crystal panel 1 using the same color image display data, when reading from the frame memory 5, the read reset signal -RRS is used as a vertical reset signal as shown in FIG. synchronizing signal (-VS) 8 ₁ of using a 6x of the signal. As a result, "the selected image display data SDA
TA ”is R → R for each frame as shown in FIG.
Are transmitted to the liquid crystal panel 1 through the source line driver 2 in the order of → G → G → B → B → R → R. The gate line driver 3 and the necessary timing source line driver 2, for example, gate start GS, the gate clock GCK, a source output OE, shift pulse DL or the like, the timing controller 6 vertical synchronizing signal 8 ₁ and the horizontal sync signal ₈₂ of the It is generated from the timing signal of each 6 times speed. On the other hand, the color light source lighting control unit 4 negates (NOT) the LC signal and outputs the color control control signals A,
R and G, respectively, using the logical product (AND) output with B and C
The B color light source is turned on.

Next, an embodiment of the present invention will be described. In the present embodiment, the same reference numerals are used for the same elements and signals as those of the reference example. In the reference example, the following color image table
To send different color images before sending
Sometimes, before and after rewriting, different colors before and after
Because images are mixed, the same color image display data is sent twice.
Second rewrite when different color images are not mixed
Turn on the color light source. Therefore, the lighting time of the color light source
There is a problem that it becomes shorter. What solved this problem
The present invention is described below with reference to one embodiment.

FIG. 4 shows the relationship between the display state on the liquid crystal panel and the lighting of the color light source in this embodiment. In the present embodiment, black data (that is, data in which the liquid crystal panel is in a light blocking state) is displayed while each of the R, G, and B color image display data is displayed on the liquid crystal panel 1, and the R color image display data is displayed. And RL and G data, respectively, for the display correspondence between G color image display data and black data, and B color image display data and black data.
The color light sources of L and BL are turned on. The R color image display data is displayed on the liquid crystal panel 1 from time t ₀ to time t ₁ , and the black data displayed on the liquid crystal panel 1 is rewritten with the R color image display data from time t ₀ , ₁
Then, rewriting is completed with the R color image display data over the entire surface of the liquid crystal panel 1. Subsequently, from time t ₁ to time t ₂ , the black data is sent to the liquid crystal panel 1 so that the liquid crystal panel 1 is set to a black display (light blocking state), and the next G color image display data is transmitted to the liquid crystal panel 1. Prepare for sending. The turning on of the R color light source is from time t ₀ to time t ₂ when black data and R color data are mixed on the liquid crystal panel. Next, the color image display data G color from time t ₂ to time t _3, the display and sends out the black data to the liquid crystal panel 1 during the time t ₃ at time t _4, the lighting of the G-color light source Time performed between t ₂ of time t _4.
Similarly, the B-color color image display data for a time t ₅ from time t _4, view and sends the black data to the liquid crystal panel 1 between times t ₆ from the time t _5, the lighting of the B-color light source is time performed between the time t ₆ from t _4.

FIG. 5 shows an embodiment of a control circuit configuration of the color image display data and the color light source at this time, and FIG. 6 shows a timing chart thereof. In FIG. 1 showing the reference example, the same color image display data is displayed twice successively, but in the present embodiment, it is displayed once. Thus, R, G, read enable signals -r _RE1 ~-r _RE3 used for reading the B-color color image display data, -f _RE1 ~-f _RE3 is a signal width shown in FIG. 3 of Reference Example 1/2 To During a period in which these read enable signals are not in an active state (memory read state), a switch for selecting black data from the switch 12 and selecting image display data read from the frame memory 5 as shown in FIG. The output ( OR ) of the selected image display data S.
DATA ”to the source line driver 2 through the AC conversion circuit 10. Therefore, the logic is the output color selection control signal A decoder 11 which receives the LC signal 3 double-speed of 2 similar vertical synchronizing signal (-VS) 8 _1, B, and each and LC signal C The output of the switch 9 is obtained by multiplying (AND) the logical product (AND) of this output and the image display data read from the frame memory 5. further,
Read enable signal of frame memory 5 -r _RE1.
r _RE3 , −f _RE1 to −f _RE3 include a logical product (AND) output of the color selection control signals A, B, C and the LC signal and a front / back selection signal −f for selecting the front or back of the frame memory 5. / R
AND NOT output with this NOT signal (NAN)
D) is used. Read reset signal used when reading from the frame memory 5 -RRS may be three double speed as shown in FIG. 6 in the signal of the vertical sync signal (-VS) 8 ₁ of 6 double-speed as shown in FIG. As a result, as shown in FIG. 6, the selected image display data S / DATA is passed through the source line driver 2 in the order of R → black → G → black → B → black → R → black. It is sent to the liquid crystal panel 1.
On the other hand, the color light source lighting control unit 4 turns on the R, G, and B color light sources by the color selection control signals A, B, and C, respectively, as shown in the timing of FIG.

In the above embodiment, as the timing required for the gate line driver 3 and the source line driver 2, for example, a gate start GS, a gate clock GCK, a source output OE, a shift pulse DL and the like are sent to a normal vertical synchronization signal (- VS) without the use of 8 ₁ and a horizontal synchronizing signal (-HS) 8 ₂ a timing signal of a constant velocity, has been described by using the timing signal of each of the 6 double speed. In accordance with this, the read enable signal, the color selection control signal, etc. of the frame memory 5 and the related timing signals, such as the LC signal, the read reset signal, etc., have also been described as being 6 times speed or 3 times speed.
This is due to the time-division lighting of the three primary color light sources,
This is because one cycle of the three primary color light sources was adjusted to a conventional vertical synchronizing signal as a speed at which flicker of the liquid crystal panel is not noticeable. Therefore, these speeds are not specified, and may be determined according to the stability of the display state on the liquid crystal display panel, the operation speed of the liquid crystal, whether to display a still image, a moving image, or both. However, there is no particular limitation.

In the above embodiment, the switches 9, 1
Although 2 has been described as having a logical product (AND) operation function, if the data read from the frame memory is not converted to analog by the AC conversion circuit but is converted to analog before passing through the switches 9 and 12, An analog switch may be considered as an analog switch. At this time, color image display data or black data is assigned to the switch input, and a color selection control signal A, B, C or a logical product output of these signals and an LC signal is used as a gate signal of the switch. Assigned.

Further, in the above embodiment, the color image display data of R, G, and B colors has been described as the color image display data of a plurality of colors. However, as the plurality of colors, magenta, yellow, and cyan are displayed. Image display data may be used, and a color corresponding to the display data may be used as the color light source. It does not matter whether or not the color image display data has a gradation. If there is a gradation, a full-color liquid crystal display can be realized. Further, the plurality of colors is not limited to the three primary colors as described above, but may be any two colors. In this case, in the description of the above-described embodiment, the speed at the various timings becomes four times the speed at the various times. To speed,
The triple speed may be considered as the double speed.

As described above, the present invention can be variously applied according to the gist thereof and can take various embodiments.

[0027]

As described above, in the color liquid crystal display system of the present invention, a black-and-white display transmissive liquid crystal panel and a color light source corresponding to the color of the color image display data are used, and one color image display data of one color is displayed. the circuit for lighting control of the color light source and the circuit unit to be sent to the liquid crystal panel with the selected time division frames at a time, sends the black data of one frame between the each color image display data of one frame transfer, prior to the color of the The data is completely erased from the liquid crystal panel display by the black data, the liquid crystal panel is kept in a light-blocking state, and the color light source of the corresponding color is turned on at the time of transferring and displaying each color image display data to the panel. . For this reason, the lighting of the color light source and the color image display data to be displayed on the liquid crystal panel match, and a color image of a faithful color can be displayed.

Since a color liquid crystal display can be performed by using a transmissive liquid crystal panel for black and white display, the number of pixels and the number of wirings can be reduced, and the structure of the liquid crystal panel is simple because no RGB color filter is required for each pixel. An improvement in panel production yield can be expected.

Further, when the multicolor light source is, for example, RGB color, an image is displayed from the same pixel in a time-division manner, so that the color liquid crystal panel has RGB color pixels arranged in different places, respectively. The light transmission area is increased about three times, and the color saturation can be increased.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between lighting of a color light source corresponding to color display image data showing a reference example of the present invention.

FIG. 2 is a circuit diagram showing an embodiment of a control circuit configuration of color image display data and a color light source in the reference example.

FIG. 3 is a timing chart for explaining the operation of the control circuit in the reference example.

FIG. 4 is a diagram showing a relationship between lighting of a color light source corresponding to color display image data showing an embodiment of the present invention.

FIG. 5 is a circuit diagram showing an embodiment of a control circuit configuration of a color image display data and the color light sources definitive on you施例

[6] above you timing chart for explaining the operation of the control circuit in施例

[Explanation of symbols]

1 ... liquid crystal display panel, 2 ... source line driver 3 ... gate line driver, 4 ... color light source lighting control unit, 5 ... frame memory, 6 ... timing controller, 7 _1, 7 _2, 7 ₃ ... R,
G, B color image display data, 8 ₁ , 8 ₂ ... vertical and horizontal synchronization signals, 9 switches, 10 alternating circuits, 11 ...
Decoder, 12 ... Switch.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G09G 3/36 G02F 1/133 550 G02F 1/133 560 G02F 1/13357 G09G 3/20 642

Claims (1)

(57) [Claims] A transmission / reception type liquid crystal panel for monochrome display, a circuit unit for selecting color image display data for each color and sending each of them to the liquid crystal panel in a time division manner, a color light source corresponding to the color of the color image display data, in the liquid crystal display device composed of a circuit for lighting control of the color light sources in synchronism with the feeding of the liquid crystal Paneruhe color image display data, the liquid crystal panel by selecting one frame at a time color image display data in a plurality of colors in time order feed Ri liquid crystal panel entirely rewritten Rutoki to, rewrites each <br/> once the liquid crystal panel entire I send the black data of one frame between each color image display data selected in black data
For example, and to conform to the selected color image display data and the black data, the corresponding color liquid crystal display system, characterized in that lit color color light sources.