Cholesteric liquid crystal display device

Abstract

The present invention discloses a cholesterol liquid crystal display device, which includes a plurality of writing terminals and a plurality of scanning terminals. The plurality of writing terminals are arranged along a first direction and have a bright state voltage and a dark state voltage. The plurality of scanning terminals are arranged along a second direction and have a selection state voltage and a non-selection state voltage. The writing terminals and the scanning terminals intersect with each other to form a plurality of intersections, and the electrical signal at each intersection is used to control pixels. The absolute value of the difference between the bright state voltage and the non-selection state voltage in the same time period is defined as a first voltage difference, and the absolute value of the difference between the dark state voltage and the non-selection state voltage in the same time period is defined as a second voltage difference, and the second voltage difference is smaller than the first voltage difference. In this way, crosstalk can be avoided on the cholesterol liquid crystal display device, and unselected pixels can be prevented from being in a display state.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid crystal display, and in particular to a cholesteric liquid crystal display device. Background Art

[0002] Cholesteric liquid crystal display is a type of liquid crystal display, in which cholesteric liquid crystal has a bistable characteristic: that is, it has two stable states when no external force is applied. This is the biggest difference from the TFT liquid crystal displays and OLED displays commonly used today.

[0003] Cholesteric liquid crystal molecules have two stable states: focal conic and planar. This makes them bistable, meaning they maintain their original molecular alignment without requiring additional energy. Applying a voltage can control the molecular alignment of the cholesteric liquid crystal to switch between the two stable states.

[0004] Current cholesteric liquid crystal displays (LCDs) often suffer from crosstalk, which disrupts the display. Crosstalk occurs when a voltage is applied to a selected pixel in a multi-voltage drive system. This occurs when leakage current affects nearby unselected pixels, causing them to display differently. This means that other pixels surrounding the selected pixel also display differently, causing interference.

[0005] Therefore, the main object of the present invention is to provide a cholesteric liquid crystal display device to solve the above problems. Summary of the Invention

[0006] The object of the present invention is to provide a cholesteric liquid crystal display device, which can avoid crosstalk on the cholesteric liquid crystal display device and prevent unselected pixels from also showing a display state, thereby ensuring the display performance of the cholesteric liquid crystal display device.

[0007] To achieve at least one of the aforementioned advantages or other advantages, one embodiment of the present invention provides a cholesteric liquid crystal display device comprising a plurality of writing terminals and a plurality of scanning terminals.

[0008] A plurality of write terminals are arranged along a first direction and have a bright-state voltage and a dark-state voltage. A plurality of scan terminals are arranged along a second direction and have a selected-state voltage and a non-selected-state voltage. The write terminals and the scan terminals intersect to form a plurality of intersections, and an electrical signal at each intersection is used to control a pixel. The absolute value of the difference between the bright-state voltage and the non-selected-state voltage in the same time period is defined as a first voltage difference, and the absolute value of the difference between the dark-state voltage and the non-selected-state voltage in the same time period is defined as a second voltage difference, and the second voltage difference is smaller than the first voltage difference.

[0009] In some embodiments, the electrical signal at each intersection is used to control the pixel to be in a bright state or a dark state. When the bright state voltage and the selection state voltage are applied to the pixel, the pixel is in a bright state. When the dark state voltage and the selection state voltage are applied to the pixel, the pixel is in a dark state.

[0010] In some embodiments, the first direction is perpendicular to the second direction.

[0011] In some embodiments, the cholesteric liquid crystal display device uses a dynamic driving method to drive the voltage.

[0012] In some embodiments, a ratio of the second voltage difference to the first voltage difference ranges from 0.7 to 0.8.

[0013] In some embodiments, the cholesteric liquid crystal display device is driven by a passive driving method.

[0014] In some embodiments, a ratio of the second voltage difference to the first voltage difference ranges from 0.8 to 0.95.

[0015] To achieve at least one of the aforementioned advantages or other advantages, another embodiment of the present invention further provides a cholesteric liquid crystal display device comprising a plurality of writing terminals and a plurality of scanning terminals.

[0016] A plurality of write terminals are arranged along a first direction and have a bright-state voltage and a dark-state voltage. A plurality of scan terminals are arranged along a second direction and have a selected-state voltage and a non-selected-state voltage. The write terminals and the scan terminals intersect to form a plurality of intersections, and an electrical signal at each intersection is used to control a pixel. The absolute value of the non-selected-state voltage is greater than half the sum of the absolute values ​​of the bright-state voltage and the dark-state voltage.

[0017] In some embodiments, an absolute value of the non-selected state voltage is smaller than an absolute value of the dark state voltage.

[0018] In some embodiments, an absolute value of the dark-state voltage is greater than an absolute value of the bright-state voltage.

[0019] Therefore, by using the cholesteric liquid crystal display device provided by the present invention, by setting the second voltage difference to be smaller than the first voltage difference, crosstalk is avoided on the cholesteric liquid crystal display device, and unselected pixels are prevented from also showing a display state, thereby ensuring the display performance of the cholesteric liquid crystal display device.

[0020] In addition, by setting the absolute value of the non-selected state voltage to be greater than 1 / 2 of the sum of the absolute values ​​of the bright state voltage and the dark state voltage, crosstalk can be avoided on the cholesterol liquid crystal display device, preventing unselected pixels from also showing a display state, thereby ensuring the display performance of the cholesterol liquid crystal display device.

[0021] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following lists preferred embodiments and describes them in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 is a schematic diagram of a cholesteric liquid crystal display device of the present invention;

[0024] Figure 2 yes Figure 1 The diagram shows the operation of a cholesteric liquid crystal display device.

[0025] Figure numerals: 10 - cholesterol liquid crystal display device; 12 - writing end; 14 - scanning end; A1, A2, A3, A4 - pixels; B - dark state voltage; W - bright state voltage; N - non-select state voltage; Y - selected state voltage; X - first direction; Z - second direction; V1 - first voltage difference; V2 - second voltage difference. DETAILED DESCRIPTION

[0026] The specific structural and functional details disclosed herein are merely representative and are for the purpose of describing exemplary embodiments of the present invention. However, the present invention may be embodied in many alternative forms and should not be construed as being limited to only the embodiments set forth herein.

[0027] In the description of the present invention, it should be understood that the terms "center", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In addition, the term "including" and any variations thereof all mean "at least including".

[0028] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integrally formed connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0029] The terms used herein are intended only to describe specific embodiments and are not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "a", "an", "an item" used herein are also intended to include the plural. It should also be understood that the terms "comprise" and / or "include" used herein specify the presence of stated features, integers, steps, operations, units and / or components, and do not preclude the presence or addition of one or more other features, integers, steps, operations, units, components and / or combinations thereof.

[0030] See also Figure 1 and Figure 2 , Figure 1 is a schematic diagram of a cholesteric liquid crystal display device 10 of the present invention, Figure 2 yes Figure 1 Schematic diagram of the operation of a cholesteric liquid crystal display device 10 is shown. To achieve at least one of the aforementioned advantages or other advantages, one embodiment of the present invention provides a cholesteric liquid crystal display device 10. As shown in the figure, the cholesteric liquid crystal display device 10 includes a plurality of writing terminals 12 and a plurality of scanning terminals 14.

[0031] The plurality of writing terminals 12 are arranged along the first direction X and have a bright state voltage W and a dark state voltage B. Figure 1 In the figure, B and the arrow direction indicate that the dark state voltage B is applied to the write end 12, and W and the arrow direction indicate that the bright state voltage W is applied to the write end 12. The plurality of scanning ends 14 are arranged along the second direction Z and have a selection state voltage Y and a non-selection state voltage N. Figure 1 In the figure, N and the arrow direction indicate that the non-selective voltage N is applied to the scanning end 14 , and Y and the arrow direction indicate that the selective voltage Y is applied to the scanning end 14 .

[0032] The writing terminals 12 and the scanning terminals 14 intersect to form a plurality of intersections, and the electrical signal at each intersection is used to control a pixel. Specifically, as shown in the figure, when the bright voltage W and the select voltage Y are simultaneously applied to pixel A1, pixel A1 is in a bright state; when the dark voltage B and the select voltage Y are simultaneously applied to pixel A2, pixel A2 is in a dark state; when the bright voltage W and the non-select voltage N are simultaneously applied to pixel A3, pixel A3 does not change and maintains its original color; when the dark voltage B and the non-select voltage N are simultaneously applied to pixel A4, pixel A4 does not change and maintains its original color. In other words, the electrical signal at each intersection is used to control whether the pixel is in a bright or dark state. When the bright voltage W and the select voltage Y are applied to the pixel, the pixel is in a bright state, and when the dark voltage B and the select voltage Y are applied to the pixel, the pixel is in a dark state.

[0033] The bright and dark states refer to the brightness of a pixel. For example, dark colors such as dark red and dark green are considered dark states, while bright colors such as bright red and bright green are considered bright states. In one embodiment, the first direction X is perpendicular to the second direction Z to form a matrix-like arrangement of intersections, facilitating voltage application and pixel control.

[0034] As shown in the figure, the absolute value of the difference between the bright-state voltage W and the non-selected-state voltage N during the same time period is defined as a first voltage difference V1, and the absolute value of the difference between the dark-state voltage B and the non-selected-state voltage N during the same time period is defined as a second voltage difference V2. By setting the second voltage difference V2 to be smaller than the first voltage difference V1, the occurrence of crosstalk in the cholesteric liquid crystal display device 10 can be effectively reduced, ensuring the display performance of the cholesteric liquid crystal display device 10. For example, if the forward voltage VP1 of the bright-state voltage W is 10V, the forward voltage VP2 of the non-selected-state voltage N is 15V, and the forward voltage VP3 of the dark-state voltage B is 18V, then the first voltage difference V1 = |VP1-VP2| = 5V, and the second voltage difference V2 = |VP3-VP2| = 3V, i.e., V2 < V1, effectively reducing the occurrence of crosstalk in the cholesteric liquid crystal display device 10.

[0035] Furthermore, the second voltage difference can be ensured to be less than the first voltage difference by ensuring that the absolute value of the non-selected voltage N is greater than half the sum of the absolute values ​​of the bright voltage W and the dark voltage B, thereby preventing crosstalk from occurring on the cholesteric liquid crystal display device 10. For example, if the forward voltage VP1 of the bright voltage W is 10V and the forward voltage VP3 of the dark voltage B is 18V, then the forward voltage VP2 of the non-selected voltage N should be greater than 14V. Assuming VP2 is 15V, the first voltage difference V1 = |VP1-VP2| = 5V and the second voltage difference V2 = |VP3-VP2| = 3V, satisfying V2 < V1. This effectively reduces crosstalk on the cholesteric liquid crystal display device 10. It should be noted that in this approach, the absolute value of the non-selected voltage N should be less than the absolute value of the dark voltage B, which should be greater than the absolute value of the bright voltage W.

[0036] Furthermore, when the cholesteric liquid crystal display device 10 uses a dynamic driving scheme, such as a DDS (Dynamic Driving Scheme) driving scheme, the ratio of the second voltage difference V2 to the first voltage difference V1 is preferably controlled within a range of 0.7 to 0.8. When the cholesteric liquid crystal display device 10 uses a dynamic driving scheme, such as a PM (Passive Matrix) PWM (Pulse Width Modulation) driving scheme, the ratio of the second voltage difference V2 to the first voltage difference V1 is preferably controlled within a range of 0.8 to 0.95.

[0037] In summary, the cholesteric liquid crystal display device 10 provided by the present invention prevents crosstalk from occurring in the cholesteric liquid crystal display device 10 by setting the second voltage difference V2 to be smaller than the first voltage difference V1, thereby preventing unselected pixels from displaying, and thus ensuring the display performance of the cholesteric liquid crystal display device 10. Furthermore, by setting the absolute value of the non-selected voltage N to be greater than 1 / 2 of the sum of the absolute values ​​of the bright-state voltage W and the dark-state voltage B, crosstalk can be prevented in the cholesteric liquid crystal display device 10, preventing unselected pixels from changing their display states, and thus ensuring the display performance of the cholesteric liquid crystal display device 10.

[0038] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the present profession can make slight changes or modifications to equivalent embodiments of equivalent changes using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A cholesteric liquid crystal display device, characterized in that: The cholesteric liquid crystal display device comprises: A plurality of writing ends are arranged along a first direction and have a bright state voltage and a dark state voltage; A plurality of scanning ends arranged along a second direction and having a selection state voltage and a non-selection state voltage, wherein the plurality of writing ends and the plurality of scanning ends intersect with each other to form a plurality of intersections, and an electrical signal at each intersection is used to control a pixel; Among them, the absolute value of the difference between the bright state voltage and the non-selected state voltage in the same time period is defined as a first voltage difference, and the absolute value of the difference between the dark state voltage and the non-selected state voltage in the same time period is defined as a second voltage difference. The second voltage difference is smaller than the first voltage difference. When the cholesterol liquid crystal display device uses a dynamic driving mode to drive the voltage, the ratio of the second voltage difference to the first voltage difference ranges from 0.7 to 0.

8. When the cholesterol liquid crystal display device uses a passive driving mode to drive the voltage, the ratio of the second voltage difference to the first voltage difference ranges from 0.8 to 0.95, so as to suppress the occurrence of crosstalk.

2. The cholesteric liquid crystal display device according to claim 1, wherein The electrical signal at each intersection is used to control the pixel to be in a bright state or a dark state. When the bright state voltage and the selection state voltage are applied to the pixel, the pixel is in a bright state. When the dark state voltage and the selection state voltage are applied to the pixel, the pixel is in a dark state.

3. The cholesteric liquid crystal display device according to claim 1, wherein The first direction is perpendicular to the second direction.

4. A cholesteric liquid crystal display device, characterized in that: The cholesteric liquid crystal display device comprises: A plurality of writing ends are arranged along a first direction and have a bright state voltage and a dark state voltage, wherein the bright state voltage is W and the dark state voltage is B; A plurality of scanning ends arranged along a second direction and having a selection state voltage and a non-selection state voltage, wherein the plurality of writing ends and the plurality of scanning ends intersect with each other to form a plurality of intersections, and an electrical signal at each intersection is used to control a pixel; Among them, the absolute value of the non-selected state voltage is N, which is greater than 1 / 2 of the sum of the absolute value of the bright state voltage and the absolute value of the dark state voltage, that is, |N|>(|W|+|B|) / 2, and the absolute value of the difference between the bright state voltage and the non-selected state voltage in the same time period is defined as a first voltage difference, and the absolute value of the difference between the dark state voltage and the non-selected state voltage in the same time period is defined as a second voltage difference, and the second voltage difference is smaller than the first voltage difference. When the cholesterol liquid crystal display device uses a dynamic driving mode to drive the voltage, the ratio of the second voltage difference to the first voltage difference is in the range of 0.7 to 0.

8. When the cholesterol liquid crystal display device uses a passive driving mode to drive the voltage, the ratio of the second voltage difference to the first voltage difference is in the range of 0.8 to 0.95, so as to suppress the occurrence of crosstalk.

5. The cholesteric liquid crystal display device according to claim 4, wherein An absolute value of the non-selection state voltage is smaller than an absolute value of the dark state voltage.

6. The cholesteric liquid crystal display device according to claim 4, wherein An absolute value of the dark-state voltage is greater than an absolute value of the bright-state voltage.

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