CN101311800B - Color cholesteric liquid crystal display device and driving method thereof - Google Patents

Abstract

The present invention provides a color cholesteric liquid crystal display device and a driving method thereof. The color cholesteric liquid crystal display has a color cholesteric liquid crystal display panel having a plurality of pixels. A driving module applies a first voltage to some pixels of the color cholesteric liquid crystal display panel to maintain the display state of the some pixels, and an input device applies pressure to the color cholesteric liquid crystal display panel to change the display state of another part of the pixels to which the first voltage is not applied.

Description

Color cholesteric liquid crystal display device and driving method thereof

technical field

The invention relates to a cholesteric liquid crystal display device, in particular to a color cholesteric liquid crystal display device and a driving method for image writing.

Background technique

Liquid crystal displays (LCDs) have many advantages, such as small size, light weight, low power consumption, and so on. Therefore, LCDs have been widely used in electronic products such as portable computers and mobile phones. That is, the liquid crystal display technology is continuously developing towards the field of being light, thin and easy to carry.

Touch LCD devices are usually applied to display screens of notebook computers and personal computers, especially portable electronic products such as personal digital assistants. Some of the flat panel displays are position-sensing displays that sense the position of the stylus when the stylus directly touches the display panel.

For example, known resistive touch position sensing displays include resistive touch panels and stylus. When the stylus directly or physically contacts the resistive touch panel of the resistive touch position sensing display, the resistive touch panel receives the touch from the stylus, so that the resistive touch position sensing display Sensing the location of the stylus.

A traditional touch LCD device is a single input LCD device by integrating a touch panel and an LCD panel. Moreover, the touch panel is arranged between the user's eyes and the liquid crystal display panel to achieve a display with handwriting input function. However, the incident light passes through the touch-sensitive panel first, causing partial reflection, causing the user to see glare (glaring light), which further reduces the image contrast of the touch-sensitive liquid crystal display device.

In order to solve the image contrast reduction caused by glare, U.S. Patent No. 6,982,432 discloses another touch-type liquid crystal display device that includes a combination of a touch-sensitive panel and a liquid crystal display panel, and the liquid crystal display panel is arranged between the user's eyes and the touch-sensitive screen. Between the panels, a display with handwriting input function is achieved.

FIG. 1 is a schematic cross-sectional view showing a conventional touch-sensitive liquid crystal display device. In FIG. 1 , the traditional touch-sensitive liquid crystal display device includes a touch-sensitive panel 4 and a liquid crystal display panel 3A, and the liquid crystal display panel 3A is disposed between the user and the touch-sensitive panel 4 . The liquid crystal display panel 3A comprises a color filter substrate 31 with an electrode layer 32 on it, a transparent substrate 36 with a transparent electrode layer 35 thereon, and a micromolecule dispersed liquid crystal layer 34 sealed 33 between the color filter substrate 31 and the transparent substrate. between the substrates 36 .

The touch panel 4 includes an electrode 41 disposed on a transparent substrate 36 , and an electrode 43 disposed on a substrate 44 . There is a gap between the electrode 41 and the electrode 43 and is sealed by a seal 42 . The pressure F applied by the sensing stylus is transmitted to the electrodes 41 and 43 of the touch panel 4 , and the position of the stylus is sensed by the electrode contact points. However, the handwriting input function and the display function are independently implemented by the touch panel and the liquid crystal display panel, and at least two independent panel structures are required, and the overall structure and process are complicated, resulting in increased manufacturing costs.

Furthermore, U.S. Patent No. US 6,392,725 discloses a color cholesteric liquid crystal display, which is composed of three different monochromatic cholesteric liquid crystal layers stacked together, and a pair of writing electrodes are arranged on the outside of the stacked panel structure, and an external electric field is used to control the Write the image.

FIG. 2 is a schematic diagram showing a conventional three-layer cholesteric liquid crystal layer stack display. Please refer to FIG. 2 , a conventional write-in cholesteric liquid crystal display device includes a stacked liquid crystal display panel 50 and a writing device 60 . The stacked liquid crystal display panel includes a pair of opposite substrates 52 and 53 interposed therebetween and three liquid crystal layers 58A, 58B and 58C of different colors are vertically stacked. The liquid crystal layers are spaced apart to separate the substrates 54 and 55 , and spacers 59A, 59B and 59C are filled in each liquid crystal layer to maintain the gap between the liquid crystal layers. The absorption plate 56 is disposed on the back of the lower substrate 53 .

The writing device 60 includes a pair of writing electrodes 61 and 62 disposed outside the structure of the stacked LCD panel 50 , and is controlled by a controller 63 to write images. The traditional write-in cholesteric liquid crystal display device has a stacked structure of three cholesteric liquid crystal layers, and different liquid crystal layers require different control voltage waveforms, resulting in complex processes and high manufacturing costs.

In addition, there is still a color cholesteric liquid crystal display in the known technology, which requires an additional light source as an input medium through a light input device from the back, which is not easy to use, and requires an additional light detection layer, resulting in a complicated structure, so the convenience of use is low and Manufacturing costs are high.

Contents of the invention

In view of this, the present invention provides a color cholesteric liquid crystal display device, which uses an input device to apply pressure and cooperates with a driving device to apply a driving voltage waveform to change the arrangement and display state of cholesteric liquid crystal molecules. Since the arrangement of the cholesteric liquid crystal molecules determines the capacitance value and light reflectivity, and because the arrangement of the cholesteric liquid crystal molecules has a bistable property, it also has the function of color image display and/or input.

The present invention also provides a color cholesteric liquid crystal display device, comprising: a color cholesteric liquid crystal display panel, which has a plurality of pixels; a driving module, which applies a first voltage to some pixels of the color cholesteric liquid crystal display panel, to maintain the part of pixels and an input device for applying a pressure on the color cholesteric liquid crystal display panel to change the display state of another part of pixels not applied with the first voltage.

The present invention provides another color cholesteric liquid crystal display device, including a color cholesteric liquid crystal display device, comprising: a color cholesteric liquid crystal display panel with a plurality of color pixels; a driving module for providing the color cholesteric liquid crystal display panel with a first voltage , to maintain the state of the color pixel; the input device applies pressure to the color cholesteric liquid crystal display panel to change the state of another color pixel to which the first voltage is not applied; and the capacitive sensor senses the respective color The display state of the pixel is stored in the memory.

The present invention also provides a driving method for a color cholesteric liquid crystal display device, including: providing a color cholesteric liquid crystal display device, which has a plurality of color sub-pixels including a first color sub-pixel, a second color sub-pixel and a third color sub-pixel pixel; the drive module outputs the first voltage waveform to the color cholesteric liquid crystal display, so that each color cholesteric liquid crystal layer is in a dark state; and the input device inputs the first color image, the second color image, and the third color image to the Color cholesteric liquid crystal display.

In order to make the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

Description of drawings

1 is a schematic cross-sectional view showing a conventional touch-sensitive liquid crystal display device;

FIG. 2 is a schematic diagram showing a conventional three-layer cholesteric liquid crystal layer stack display;

3 is a schematic cross-sectional view showing a cholesteric liquid crystal display device according to an embodiment of the present invention;

4A and 4B respectively show the schematic diagrams of the molecular arrangement of the planar texture state and the focal conic texture state of the cholesteric liquid crystal;

5 is a schematic diagram showing the relationship between the voltage and the reflectivity of the mutual conversion between the planar texture and the focal conic texture of the cholesteric liquid crystal display under an applied voltage;

6A and 6B are cross-sectional schematic diagrams showing the principle of measuring the capacitance value of the planar texture and the focal conic texture of the cholesteric liquid crystal, respectively;

7A-7C are schematic cross-sectional views showing a single-layer color cholesteric liquid crystal display device according to an embodiment of the present invention;

7D-7F are schematic cross-sectional views showing a multilayer color cholesteric liquid crystal display device according to another embodiment of the present invention;

8 is a schematic diagram showing the relationship between the voltage and the reflectance of each liquid crystal layer of the color cholesteric liquid crystal display according to an embodiment of the present invention, which is converted from a planar texture to a focal conic texture under an applied voltage;

9A is a schematic block diagram showing a color cholesteric liquid crystal display device according to an embodiment of the present invention;

9B is a schematic block diagram showing a color cholesteric liquid crystal display device according to another embodiment of the present invention;

10A is a flowchart showing a driving method of a color cholesteric liquid crystal display device according to an embodiment of the present invention;

10B is a flowchart showing a driving method of a color cholesteric liquid crystal display device according to an embodiment of the present invention; and

11A-11E are schematic diagrams showing display states of the cholesteric liquid crystal display at various stages of handwriting input according to an embodiment of the present invention.

Explanation of reference signs

Known part (Figure 1～2)

3A～LCD display panel; 4～touch panel;

31～color filter layer substrate; 32～electrode layer;

33～sealing; 34～micromolecule dispersed liquid crystal layer;

35～transparent electrode layer; 36～transparent substrate;

41～electrode; 42～seal;

43～electrode; 44～substrate;

F～pressure; 50～stacked LCD panel;

52, 53～facing the substrate; 54, 55～isolated substrate;

58A, 58B, 58C～spacers; 58A, 58B, 58C～liquid crystal layers of different colors;

60～writing device; 61, 62～writing electrodes;

63 ~ controller.

Part of this application (Figure 3～11E)

100～cholesteric liquid crystal display; 110～the first substrate;

120～first electrode; 130～liquid crystal layer;

140～second electrode; 150～second substrate;

310～lower substrate; 320～upper substrate;

330～absorbing layer; 350～liquid crystal layer;

L _I ~incident light; L _R ~reflected light;

700a, 700b～color cholesteric liquid crystal display;

701～the first substrate;

702R, 702G, 702B～color sub-pixel layer;

703R, 705R～red sub-pixel electrode pair;

704R～red liquid crystal layer; 703G, 705G～green sub-pixel electrode pair;

704G～green liquid crystal layer; 703B, 705B～blue sub-pixel electrode pair;

704B～blue liquid crystal layer; 707, 708, 725, 735～insulating layer;

710～the first substrate; 720～the first electrode;

730～liquid crystal layer; 740～second electrode;

750～second substrate; R, G, B～color sub-pixels;

800R, 800G, 800B~Corresponding to the curves of liquid crystal molecules in the liquid crystal layer of each color changing from planar texture to focal conic texture;

900～color cholesteric liquid crystal display device;

910a, 900b～color cholesteric liquid crystal display panels;

920～column controller; 930～row controller;

940～input device; 950～drive module;

960～capacitive sensor; 970～memory;

S1001-S1003～the process steps of the driving method;

S1010-S1090～the process steps of the driving method;

1100R～red display area; 1100G～green display area;

1100B～blue display area; 1110R, 1110G, 1110B～erasing area.

Detailed ways

An embodiment of the present invention provides a color cholesteric liquid crystal display device, which utilizes the characteristics of cholesteric liquid crystals. For example, if there is no external voltage, applying pressure will make it change from a focal conic texture (F-state) to a planar texture ( P-state). Moreover, if a specific applied voltage is applied, the external pressure will not change the focal conic texture (F-state) into the planar texture (P-state). According to this feature, a color cholesteric liquid crystal display with color handwriting input function is designed.

FIG. 3 is a schematic cross-sectional view showing a cholesteric liquid crystal display device according to an embodiment of the present invention. Referring to FIG. 3 , the cholesteric liquid crystal display 100 includes a first substrate 110 and a second substrate 150 disposed opposite to each other, with a cholesteric liquid crystal layer 130 interposed therebetween. The cholesteric liquid crystal display 100 has a single region or multiple regions, wherein each region of the cholesteric liquid crystal display corresponds to one or more pixels.

The cholesteric liquid crystal display 100 can be a passive cholesteric liquid crystal display, wherein the first substrate 110 has a first electrode 120 along a first direction, and the second substrate 150 has a second electrode 140 along a second direction, and The first direction and the second direction are perpendicular to each other.

Alternatively, the cholesteric liquid crystal display 100 is an active cholesteric liquid crystal display, including an array composed of a plurality of pixels. Each pixel of an active cholesteric liquid crystal display includes a thin film transistor and a storage capacitor. The liquid crystal layer 130 is cholesteric liquid crystal, and has bistable states of planar texture state and focal conic texture state. Alternatively, the liquid crystal layer may be a twisted nematic liquid crystal containing an optical active agent. When the liquid crystal layer is under pressure, the alignment state of its liquid crystal molecules changes from a first state (such as a focal conic texture) to a second state (such as a planar texture), wherein the liquid crystal layer 130 has a first state in the first state. The capacitance value (eg Cf), and the liquid crystal layer has a second capacitance value (eg Cp) in the second state, and the first capacitance value Cf is not substantially equal to the second capacitance value Cp.

Since the arrangement of cholesteric liquid crystal molecules has at least a bistable state, after updating the display screen, the display screen can still be maintained after the power is removed, so it is suitable for making electronic paper and e-books.

4A and 4B are schematic diagrams showing the molecular arrangement of planar texture state and focal conic texture state of cholesteric liquid crystal, respectively. In FIGS. 4A and 4B , the cholesteric liquid crystal display includes an upper substrate 320 , a lower substrate 310 , an absorbing layer 330 disposed on the back of the lower substrate 310 , and a liquid crystal layer 350 between the upper and lower substrates. Since the arrangement of cholesteric liquid crystal molecules has at least a bistable state, in the initial state such as a planar texture state, the liquid crystal molecules consistently reflect the incident light L _I , and the reflected light L _R shows a bright state, as shown in FIG. 4A Show. As the applied voltage increases, the liquid crystal molecules transform into a focal conic texture state, and the liquid crystal molecules scatter the incident light L _I to display a dark state, as shown in FIG. 4B .

5 is a schematic diagram showing the relationship between the voltage and the reflectivity of the mutual conversion between the planar texture state and the focal conic texture state (focal conic texture state) of the cholesteric liquid crystal display under an applied voltage. The initial state of the liquid crystal molecules can be a planar texture or a focal conic texture. As the voltage increases, the alignment state of the liquid crystal molecules can change from a planar texture to a focal conic texture, or from a focal conic texture. into a planar state texture, as shown in the transition between voltages V1, V2, V3, and V4 in Figure 5.

According to an embodiment of the present invention, the liquid crystal layer has a first capacitance value (such as Cf) in the first state, and the liquid crystal layer has a second capacitance value (such as Cp) in the second state, and the first capacitance value Cf is not substantially equal to the second capacitance Cp. By measuring the capacitance change between the capacitance value Cf and the capacitance value Cp, the state of the molecules of the liquid crystal layer after a certain area of the display is subjected to external pressure can be known, which is used as the basis for the operation principle of the cholesteric liquid crystal display.

FIGS. 6A and 6B are cross-sectional schematic diagrams showing the capacitance measurement principle of planar texture state and focal conic texture state of cholesteric liquid crystal, respectively. By providing a relatively low voltage, such as 1-5V, this voltage can be used to measure the capacitance value of the liquid crystal in its state without causing phase-to-phase distortion. By providing the voltage signal, induced charges of different liquid crystals are generated, and then the capacitance values Cp and Cf are measured by the capacitance sensor, as shown in FIGS. 6A and 6B respectively. According to a preferred embodiment of the present invention, the capacitance Cp of the planar texture is 2.9nF, and the capacitance Cf of the focal conic texture is 5.2nF.

7A-7C are schematic cross-sectional views showing a single-layer color cholesteric liquid crystal display device according to an embodiment of the present invention. Please refer to FIG. 7A , a color cholesteric liquid crystal display 700a includes a single-layer color cholesteric liquid crystal display panel, which has a plurality of color sub-pixels R, G, B. Referring to FIG. Each color sub-pixel includes a gap between the first substrate 710 and the second substrate 750 , and the color cholesteric liquid crystal layer 730 is sandwiched between the first substrate 710 and the second substrate 750 corresponding to the color sub-pixel. The color cholesteric liquid crystal layer 730 has at least a first display state and a second display state, and the first display state is not substantially equal to the second display state.

The color cholesteric liquid crystal display 700a may be a passive cholesteric liquid crystal display, which is located on the first substrate 710 and has a first electrode 720 along a first direction, and has a second electrode 740 on a second substrate 750 along a second direction, And the first direction and the second direction are perpendicular to each other.

Alternatively, the first electrode 720 on the first substrate 710 is a full-surface electrode, and the second electrode 740 on the second substrate 750 is a strip electrode corresponding to the color cholesteric liquid crystal layer 730 .

According to an embodiment of the present invention, the second substrate (such as the upper substrate) 750 is a flexible substrate, such as a polycarbonate (PC) substrate, a polyethersulfone resin (PES) substrate, a polyethylene terephthalate (PET) substrate , polyimide (PI) substrate, polyorthobornene (PNB) substrate, polyether ether ketone (PEEK) substrate, polyethylene naphthalate (polyethylene napthalate, PEN) substrate, polyetherimide (PEI) substrate or polyaromatic ester (PAR) substrates.

Alternatively, the color cholesteric liquid crystal display 700a is an active cholesteric liquid crystal display, including an array of a plurality of pixels. Each pixel of an active cholesteric liquid crystal display includes a thin film transistor and a storage capacitor.

Please refer to FIG. 7B , the color cholesteric liquid crystal display 700 b has an insulating layer 725 located between the color cholesteric liquid crystal 730 and the first electrode 720 .

Please refer to FIG. 7C , the color cholesteric liquid crystal display 700c has an insulating layer 735 located between the color cholesteric liquid crystal 730 and the second electrode 740 .

7D-7F are schematic cross-sectional views showing a multilayer color cholesteric liquid crystal display device according to another embodiment of the present invention. Please refer to FIG. 7D , the color cholesteric liquid crystal display 700bd is a multi-layer color cholesteric liquid crystal display panel, which includes a plurality of color sub-pixel layers 702R, 702G, 702B between the first substrate 701 and the second substrate 706 facing each other. . Each color sub-pixel layer 702R, 702G, 702B respectively has at least a first display state and a second display state, and the first display state is not substantially equal to the second display state.

Each color sub-pixel layer 702R, 702G, 702B includes a pair of electrodes, for example, a red liquid crystal layer 704R is sandwiched between the red sub-pixel electrode pair 703R, 705R; a green liquid crystal layer 704G is sandwiched between the green sub-pixel electrode pair 703G, 705G; A blue liquid crystal layer 704B is sandwiched between the pair of blue sub-pixel electrodes 703B and 705B. Each electrode pair is electrically connected to the driving module respectively, wherein an insulating layer (not shown) is provided on the surface of each electrode to prevent direct contact between the electrodes. Wherein, each pair of electrodes, 703R, 705R and 703G, 705G and 703B, 705B, can be a whole surface electrode or a passive matrix (passive matrix) electrode.

According to an embodiment of the present invention, the second substrate (such as the upper substrate) 706 is a flexible substrate, such as a polycarbonate (PC) substrate, a polyethersulfone resin (PES) substrate, a polyethylene terephthalate (PET) substrate , polyimide (PI) substrate, polyorthobornene (PNB) substrate, polyether ether ketone (PEEK) substrate, polyethylene naphthalene (PEN) substrate, polyetherimide (PEI) substrate or polyarylate (PAR ) substrate.

Please refer to FIG. 7E , a color cholesteric liquid crystal display 700e has an insulating layer 707 located between each color liquid crystal layer (704R, 704G, 704B) and each pair of electrodes (703R, 705R and 703G, 705G and 703B, 705B).

Please refer to FIG. 7F, a color cholesteric liquid crystal display 700f has an insulating layer 708 located between each pair of electrodes (703R, 705R and 703G, 705G and 703B, 705B).

The liquid crystal layer of each color sub-pixel is cholesteric liquid crystal, and has bistable states of planar texture state and focal conic texture state. Alternatively, the liquid crystal layer may be a twisted nematic liquid crystal containing an optical active agent. When the liquid crystal layer is under pressure, the alignment state of the liquid crystal molecules changes from a first state (eg, focal conic texture) to a second state (eg, planar texture).

According to the characteristics of the cholesteric liquid crystal, for example, if no voltage is applied, applying pressure to the liquid crystal layer will change the focal conic texture (F-state) to the planar texture (P-state). Moreover, if a specific applied voltage is applied, the external pressure will not change the focal conic texture (F-state) into the planar texture (P-state). According to this feature, a color cholesteric liquid crystal display with color handwriting input function is designed. The relationship between the state of the cholesteric liquid crystal and the applied voltage and the external pressure is listed in Table 1.

Table I

The cholesteric liquid crystal is in the F-state, and the pressure is applied The cholesteric liquid crystal is in the P-state, and the pressure is applied No applied voltage From F-state to P-state Still maintain the P-state With external voltage Still maintain the F-state From P-state to F-state

FIG. 8 is a graph showing the mutual conversion between planar texture state and focal conic texture state for each liquid crystal layer of a color cholesteric liquid crystal display according to an embodiment of the present invention under an applied voltage. Schematic diagram of the relationship between voltage and reflectivity. Curves 800R, 800G, and 800B indicate that the initial state of the liquid crystal molecules in the liquid crystal layer of each color can be a planar texture or a focal conic texture, and as the voltage increases, the arrangement state of the liquid crystal molecules can change from a planar texture to a focal Cone texture, or the transformation from focal conic texture to planar texture. It should be noted that the responses of different colored liquid crystal layers to voltages are different, so in some embodiments, different driving voltages and waveforms need to be provided for different colored liquid crystal layers.

FIG. 9A is a schematic block diagram showing a color cholesteric liquid crystal display device according to an embodiment of the present invention. Please refer to FIG. 9A , a color cholesteric liquid crystal display device 900a includes a color cholesteric liquid crystal display 910 having a plurality of pixels. The driving module 950 applies a first voltage to some pixels of the color cholesteric liquid crystal display 910 to maintain the display state of the some pixels. The input device 940 exerts pressure on the color cholesteric liquid crystal display 910 to change the display state of another part of pixels not applied with the first voltage. That is, the display state of the cholesteric liquid crystal layer is changed from the focal conic texture state to the planar texture state.

FIG. 9B is a schematic block diagram showing a color cholesteric liquid crystal display device according to another embodiment of the present invention. Please refer to FIG. 9B , a color cholesteric liquid crystal display device 900b includes a color cholesteric liquid crystal display 910 having a first substrate and a second substrate opposite to each other with a cholesteric liquid crystal layer interposed therebetween, wherein the cholesteric liquid crystal layer has at least a first A display state and a second display state, and the first display state is not substantially equal to the second display state. The input device 940 exerts pressure on the cholesteric liquid crystal display 910 to change the display state of the cholesteric liquid crystal layer from the focal conic texture state to the planar texture state. The screen display of the color cholesteric liquid crystal display 910 is controlled by the column controller 920 and the row controller 930 to control the screen information. The capacitive sensor 960 senses the display state of the cholesteric liquid crystal layer, and outputs a first sensing result or a second sensing result, which is stored in the memory 970 . The driving module 950 provides a voltage waveform for the cholesteric liquid crystal display to update the display state of the cholesteric liquid crystal display to become the focal conic texture state. According to a preferred embodiment of the present invention, the memory 970 is built into the color cholesteric liquid crystal display 910 . Alternatively, the memory 970 can be built into the driving module 950 or the capacitive sensor 960 . Furthermore, the capacitive sensor 960 can be optionally built into the driving module 950 .

FIG. 10A is a flowchart showing a driving method of a color cholesteric liquid crystal display device according to an embodiment of the present invention. First, a color cholesteric liquid crystal display device is provided (eg step S1001 ), which has a plurality of pixels. The plurality of pixels include a first color sub-pixel, a second color sub-pixel and a third color sub-pixel, which cooperate with a driving module. Next, the moving module outputs a first voltage waveform to some pixels of the color cholesteric liquid crystal display to maintain its display state (such as step S1002). Next, a pressure is applied to the color cholesteric liquid crystal display panel by the input device to change the display state of another part of the pixels not applied with the first voltage (such as step S1003). For example, a first-color image, a second-color image, and a third-color image are sequentially input to the color cholesteric liquid crystal display with a handwriting input device.

FIG. 10B is a flowchart showing a driving method of a color cholesteric liquid crystal display device according to an embodiment of the present invention. Firstly, a color cholesteric liquid crystal display device is provided, the plurality of color sub-pixels include a first color sub-pixel, a second color sub-pixel and a third color sub-pixel, wherein the capacitive sensor cooperates with a driving module. Next, the driving module outputs a first voltage waveform to the color cholesteric liquid crystal display, so that each color cholesteric liquid crystal layer is in a dark state ( S1010 ). Inputting a first color image into the color cholesteric liquid crystal display with an input device (S1020), inputting a second color image into the color cholesteric liquid crystal display with the input device (S1030), and inputting a third color image into the color cholesteric liquid crystal display with the input device The liquid crystal display (S1040), using the input device to input a black image to the color cholesteric liquid crystal display (S1050). The driving module outputs the capacitive sensing voltage waveform to the cholesteric liquid crystal display (S1060). The capacitance sensor is used to sense the capacitance value of each color cholesteric liquid crystal layer (S1070), and through a specific algorithm (Algorithm), it can be known that the display state of each pixel is a dark state (F-state) or a bright state (P-state) state) (S1080). And store the display state of each color cholesteric liquid crystal layer in the memory (S1090).

More specifically, the cholesteric liquid crystal display device of the present invention can be operated by the following control method. First, execute the update action (reset) to update the display data of the color liquid crystal display panel. For example, output the first voltage waveform (for example, F-state control voltage waveform) through the driving module, and update each pixel of the color liquid crystal display panel to F-state (that is, display a dark state), as a preparatory action before color handwriting input , as shown in Figure 11A. Next, please refer to FIG. 11B , the first writing operation is performed by the handwriting input device, and the first color (red) image 1100R is input to the color cholesteric liquid crystal display. For example, the driving module outputs specific voltages (for example, 5 volts (V)) for the sub-pixels of the second color (green) and the third color (blue), and then an input device such as a stylus or any other hard point , directly perform handwriting input in the first color (red) on the surface of the display panel. According to the properties of cholesteric liquid crystals listed in Table 1, the pressed area will show the first color (red, P-state), while the unpressed sub-pixels will still show the dark state (F-state). For another example, the driving module provides a red writing voltage waveform, so that the applied voltage of the plurality of green sub-pixels is less than 1000 volts, and the applied voltage of the plurality of blue sub-pixels is less than 1000 volts. Then, the input device exerts pressure on a partial area of the color cholesteric liquid crystal display, so that a plurality of color sub-pixels in the partial area display red.

Next, please refer to FIG. 11C , the second writing operation is performed by the handwriting input device, and the second color (green) image 1100G is input to the color cholesteric liquid crystal display. For example, the drive module outputs specific voltages (such as 5 volts (V)) for the first color (red) and third color (blue) sub-pixels respectively, and then input devices such as a stylus or any other hard tip , and directly perform second-color (green) handwriting input on the surface of the display panel. At this time, the areas that are pressed are the areas that have been previously handwritten and displayed in red. After being pressed again, they will be erased (erase) and return to the dark state (F-state). The display in this area only displays the second color (green, P-state). And another kind of stressed area is the area that was not previously handwritten in red, and the second color (green, P-state) is displayed directly after being stressed. Moreover, the unpressed area is also divided into two types: one is the area that has been handwritten in the first color (red) before, and still maintains the display state of the first color (red, P-state). The other is an area that has not been previously handwritten to display the first color (red), and remains in the dark state (F-state). For another example, the green writing voltage waveform is provided by the driving module, so that the applied voltage of the plurality of red sub-pixels is less than 1000 volts, and the applied voltage of the plurality of blue sub-pixels is less than 1000 volts. Then, the input device exerts pressure on a partial area of the color cholesteric liquid crystal display, so that a plurality of color sub-pixels in the partial area display green.

Next, please refer to FIG. 11D , the third writing operation is performed by the handwriting input device, and the third color (blue) image 1100B is input to the color cholesteric liquid crystal display. For example, the drive module outputs specific voltages (for example, 5 volts (V)) for the sub-pixels of the first color (red) and the second color (green), and then uses the input device to directly perform the third color (blue) on the surface of the display panel. color) handwriting input. The area under pressure at this time is divided into three types: one is the area that has been handwritten to display the first color (red), according to the characteristics of cholesteric liquid crystal listed in Table 1, after being pressed again, the red color will be erased (erase) Return to the dark state (F-state), the display in this area only displays the third color (blue, P-state), and the other is the area that has been handwritten to display the second color (green) before, after being subjected to After pressing, the green color will be erased and return to the dark state (F-state). The display in this area only displays the third color (blue, P-state), and the other is the first color (red) that has not been handwritten before. Or the area of the secondary color (green), after the initial stress, the display in this area only shows the tertiary color (blue, P-state). On the other hand, the unpressed area still maintains the original display state. For another example, the blue writing voltage waveform is provided by the driving module, so that the applied voltage of the plurality of red sub-pixels is less than 1000 volts, and the applied voltage of the plurality of green sub-pixels is less than 1000 volts. Then, the input device exerts pressure on a partial area of the color cholesteric liquid crystal display, so that the plurality of color sub-pixels in the partial area appear blue.

Next, a sense and memory action is performed to detect and store the display data input by the user's handwriting. For example, the driving control circuit is used to detect the state of each pixel of the display panel. The detection method is as follows: First, for each pixel of the display panel, the drive control circuit outputs a specific voltage waveform for detecting the pixel capacitance value, and with memory and a specific algorithm (Algorithm), it can be known that the display state of each pixel is a dark state ( F-state) or bright state (P-state), and the voltage waveform of the detection pixel capacitance value has the function of correctly detecting the pixel state in the shortest time. After the state of the pixel is detected, it is stored in the memory, and then the above operation is repeated for the next pixel until the state of all pixels is detected and stored.

The specific algorithm (Algorithm) is as follows: the first step is to detect the capacitance value of the pixel to obtain the capacitance value C1, and store C1 in the memory; the second step is to drive the pixel to a dark state F-state ( or bright state P-state); the third step is to detect the capacitance value of the pixel again to obtain the capacitance value C2, and store C2 in the memory; the fourth step is to compare C1 and C2, if C1=C2, then it can be known The display state of this pixel is dark state F-state (or bright state P-state), if C1≠C2, then it can be known that the display state of this pixel is bright state P-state (or dark state F-state), at this time, The pixel must then be driven to the bright P-state (or dark F-state).

Then, if it is desired to perform an erasing action, the handwriting input device can be used to perform a pattern erasing action. For example, please refer to Figure 11E, the driving module outputs a specific voltage (for example, 5V) for the sub-pixel regions of all color cholesteric liquid crystal panels, and then uses the handwriting input device to directly perform handwriting erasing on the panel surface for the pattern to be erased. remove action. According to the characteristics of cholesteric liquid crystals listed in Table 1, the dark state (F-state) remains in the dark state (F-state) in the area under pressure, while the bright state (P-state) will turn into a dark state (F-state). , as shown in the areas 1110R, 1110G, and 1110B, so that the purpose and effect of erasing the pattern can be achieved.

For example, use the handwriting input device to input a black image on the color cholesteric liquid crystal display. The black writing voltage waveform can be provided by the driving module, so that the applied voltage of the plurality of red sub-pixels is less than 1000 volts, and the applied voltage of the plurality of green sub-pixels is less than 1000 volts, and the applied voltage of the plurality of blue sub-pixels Less than 1000 volts. Then, the input device exerts pressure on a partial area of the color cholesteric liquid crystal display, so that a plurality of color sub-pixels in the partial area appear black.

The embodiment of the present invention achieves the function of both handwriting input and display through the means of "specially designed applied voltage and applied pressure" and "detection of capacitance change of cholesteric liquid crystal". Input function and display function. Furthermore, the arrangement of cholesteric liquid crystal molecules can be changed by external pressure, and because the arrangement of cholesteric liquid crystal molecules determines the capacitance value and light reflectivity, the arrangement of cholesteric liquid crystal molecules has a bistable principle, so that the cholesteric liquid crystal of the display medium has both detection The detection medium for handwriting input data makes the cholesteric liquid crystal display both display and/or input functions. Furthermore, due to its relatively simplified structure and process, its manufacturing cost is greatly reduced.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the scope of the present invention. Any skilled person in the technical field may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the claims of the present invention.

Claims (40)

1. colourful cholesterin liquid-crystal display device comprises:

The color cholesterol display panels, it has a plurality of pixels;

Driver module imposes partial pixel one first voltage of this color cholesterol display panels, to keep the show state of this partial pixel; And

Input media imposes a pressure on this color cholesterol display panels, to change the show state of another part pixel that does not apply this first voltage.

2. colourful cholesterin liquid-crystal display device as claimed in claim 1, wherein this color cholesterol display panels is a single layer structure, it comprises:

Have the weir wall construction between first substrate and the second substrate subtend setting, separate a plurality of colored sub-pixels; And

Corresponding each this colored sub-pixels of a plurality of color cholesterol liquid crystal layers is folded between this first substrate and this second substrate, and is isolated by this weir wall construction.

3. colourful cholesterin liquid-crystal display device as claimed in claim 2 wherein has first electrode on this first substrate, has second electrode on this second substrate, and this first electrode or this second electrode, corresponding each this colored sub-pixels.

4. colourful cholesterin liquid-crystal display device as claimed in claim 3 also comprises insulation course, between these a plurality of color cholesterol liquid crystal layers and this first electrode or this second electrode.

5. colourful cholesterin liquid-crystal display device as claimed in claim 2, wherein this color cholesterol display panels is passive cholesterin liquid-crystal display, wherein has first electrode on this first substrate along first direction, have second electrode on this second substrate, and first direction is vertical in fact mutually with second direction along second direction.

6. colourful cholesterin liquid-crystal display device as claimed in claim 2, wherein this colourful cholesterin liquid-crystal display is active color cholesterol type LCD device.

7. colourful cholesterin liquid-crystal display device as claimed in claim 2, wherein this first substrate or this second substrate are flexible base plate.

8. colourful cholesterin liquid-crystal display device as claimed in claim 1, wherein each color cholesterol liquid crystal layer comprises corresponding coloured dye or contains the twisted nematic liquid crystal of chiral dope.

9. colourful cholesterin liquid-crystal display device as claimed in claim 1, wherein this color cholesterol display panels is a sandwich construction, it comprises:

Substrate; And

The multi layer colour cholesteric liquid crystal layer is stacked and placed on this substrate.

10. colourful cholesterin liquid-crystal display device as claimed in claim 9, wherein each color cholesterol liquid crystal layer all has first electrode and second electrode, and each color cholesterol liquid crystal layer is folded between this first electrode and this second electrode.

11. colourful cholesterin liquid-crystal display device as claimed in claim 10 also comprises insulation course, between this each color cholesterol liquid crystal layer and this first electrode or this second electrode.

12. colourful cholesterin liquid-crystal display device as claimed in claim 9 also comprises insulation course, between this each color cholesterol liquid crystal layer.

13. colourful cholesterin liquid-crystal display device as claimed in claim 9 also comprises protective seam, is stacked and placed on this multi layer colour cholesteric liquid crystal layer.

14. colourful cholesterin liquid-crystal display device as claimed in claim 9, wherein this substrate is a flexible base plate.

15. colourful cholesterin liquid-crystal display device as claimed in claim 13, wherein this protective seam or this substrate are flexible base plate.

16. colourful cholesterin liquid-crystal display device as claimed in claim 1, wherein each pixel comprises pair of electrodes, and it electrically connects this driver module, wherein has insulation course on this surface at least one electrode in the electrode.

17. cholesterin liquid-crystal display device as claimed in claim 1, wherein this driver module provides this color cholesterol display panels one capacitance sensing voltage waveform, for the show state of each color cholesterol liquid crystal layer of capacitance sensor sensing.

18. colourful cholesterin liquid-crystal display device as claimed in claim 17, wherein this capacitance sensor is built in this driver module in being.

19. colourful cholesterin liquid-crystal display device as claimed in claim 17 also comprises the liquid crystal arrangement state of this each color cholesterol liquid crystal layer of capacitance sensor sensing of memory storage, wherein this storer is built in this driver module or this capacitance sensor in being.

20. colourful cholesterin liquid-crystal display device as claimed in claim 1, wherein

These a plurality of pixels are a plurality of colour elements; This colourful cholesterin liquid-crystal display device also comprises capacitance sensor, the show state of this each colour element of difference sensing, and be stored in the storer.

21. colourful cholesterin liquid-crystal display device as claimed in claim 20, wherein this color cholesterol display panels is a single layer structure, and it comprises:

Have the weir wall construction between first substrate and the second substrate subtend setting, separate a plurality of colored sub-pixels; And

Corresponding each this colored sub-pixels of a plurality of color cholesterol liquid crystal layers is folded between this first substrate and this second substrate, and is isolated by this weir wall construction.

22. colourful cholesterin liquid-crystal display device as claimed in claim 21, wherein this color cholesterol display panels is passive cholesterin liquid-crystal display, wherein has first electrode on this first substrate along first direction, have second electrode on this second substrate, and first direction is vertical in fact mutually with second direction along second direction.

23. colourful cholesterin liquid-crystal display device as claimed in claim 22 also comprises insulation course, between these a plurality of color cholesterol liquid crystal layers and this first electrode or this second electrode.

24. colourful cholesterin liquid-crystal display device as claimed in claim 21, wherein this first substrate or this second substrate are flexible base plate.

25. colourful cholesterin liquid-crystal display device as claimed in claim 20, wherein this color cholesterol display panels is a sandwich construction, and it comprises:

Substrate; And

The multi layer colour cholesteric liquid crystal layer is stacked and placed on this substrate.

26. colourful cholesterin liquid-crystal display device as claimed in claim 25, wherein each color cholesterol liquid crystal layer all has first electrode and second electrode, and each color cholesterol liquid crystal layer is folded between this first electrode and this second electrode.

27. colourful cholesterin liquid-crystal display device as claimed in claim 26 also comprises insulation course, between this each color cholesterol liquid crystal layer and this first electrode or this second electrode.

28. colourful cholesterin liquid-crystal display device as claimed in claim 25 also comprises insulation course, between this each color cholesterol liquid crystal layer.

29. colourful cholesterin liquid-crystal display device as claimed in claim 25 also comprises protective seam, is stacked and placed on this multi layer colour cholesteric liquid crystal layer.

30. colourful cholesterin liquid-crystal display device as claimed in claim 25, wherein this substrate is a flexible base plate.

31. colourful cholesterin liquid-crystal display device as claimed in claim 29, wherein this protective seam or this substrate are flexible base plate.

32. colourful cholesterin liquid-crystal display device as claimed in claim 25, wherein each color cholesterol liquid crystal layer comprises pair of electrodes, and it electrically connects this driver module, and wherein this is to having insulation course on the surface that has an electrode in the electrode at least.

33. the driving method of a colourful cholesterin liquid-crystal display device comprises:

A kind of colourful cholesterin liquid-crystal display device as claimed in claim 1 is provided, and these a plurality of pixels comprise first look time pixel, second look time pixel and the 3rd look time pixel;

Export first voltage waveform to this colourful cholesterin liquid-crystal display by this driver module, make these a plurality of pixels all be dark attitude; And

Import the first look image, the second look image, the 3rd look image in this colourful cholesterin liquid-crystal display with input media.

34. the driving method of colourful cholesterin liquid-crystal display device as claimed in claim 33 also comprises;

By this driver module output capacitance sensing voltage waveform to this cholesterin liquid-crystal display; And

With the show state of each pixel of capacitance sensor difference sensing, and export first sensing result or second sensing result respectively, be stored in the storer.

35. the driving method of colourful cholesterin liquid-crystal display device as claimed in claim 33 also comprises with this input media input black image in this color cholesterol display panels.

36. the driving method of colourful cholesterin liquid-crystal display device as claimed in claim 33 is wherein imported the first look image with this input media and is comprised in the step of this colourful cholesterin liquid-crystal display:

Provide first look to write voltage waveform by this driver module, the impressed voltage that makes these a plurality of second looks time pixel is less than 1000 volts, and the impressed voltage of these a plurality of the 3rd looks time pixel is less than 1000 volts; And

Bestow the subregion of pressure by this input media, make this subregion present first look in this colourful cholesterin liquid-crystal display.

37. the driving method of colourful cholesterin liquid-crystal display device as claimed in claim 33 is wherein imported the second look image with this input media and is comprised in the step of this colourful cholesterin liquid-crystal display:

Provide second look to write voltage waveform by this driver module, the impressed voltage that makes these a plurality of first looks time pixel is less than 1000 volts, and the impressed voltage of these a plurality of the 3rd looks time pixel is less than 1000 volts; And

Bestow the subregion of pressure by this input media, make this subregion present second look in this colourful cholesterin liquid-crystal display.

38. the driving method of colourful cholesterin liquid-crystal display device as claimed in claim 33 is wherein imported the 3rd look image with this input media and is comprised in the step of this colourful cholesterin liquid-crystal display:

Provide the 3rd look to write voltage waveform by this driver module, the impressed voltage that makes these a plurality of first looks time pixel is less than 1000 volts, and the impressed voltage of these a plurality of second looks time pixel is less than 1000 volts; And

Bestow the subregion of pressure by this input media, make this subregion present the 3rd look in colourful cholesterin liquid-crystal display.

39. the driving method of colourful cholesterin liquid-crystal display device as claimed in claim 35 wherein comprises in the step of this colourful cholesterin liquid-crystal display with this input media input black image:

Provide black to write voltage waveform by this driver module, the impressed voltage that makes these a plurality of first looks time pixel is less than 1000 volts, and the impressed voltage of these a plurality of second looks time pixel is less than 1000 volts, and the impressed voltage of these a plurality of the 3rd looks time pixel is less than 1000 volts; And

Bestow the subregion of pressure by this input media, make this subregion present black in this colourful cholesterin liquid-crystal display.

40. the driving method of a colourful cholesterin liquid-crystal display device comprises:

A kind of colourful cholesterin liquid-crystal display device as claimed in claim 20 is provided, and these a plurality of colour elements comprise first look time pixel, second look time pixel and the 3rd look time pixel;

Export first voltage waveform to this colourful cholesterin liquid-crystal display by this driver module, make these a plurality of colour elements all be dark attitude;

Import the first look image, the second look image, the 3rd look image in this colourful cholesterin liquid-crystal display with input media.

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