Driving method of color display screen

Abstract

The invention relates to a driving method of a color display screen, and the display screen comprises RED cholesteric liquid crystal, GREED cholesteric liquid crystal and BLUE cholesteric liquid crystal. The method comprises the following steps: after a pair of first low-frequency high-voltage positive and negative pulses which are the same in frequency, same in voltage amplitude and opposite in phase are loaded to a strip-shaped electrode of a row electrode and a strip-shaped electrode of a column electrode layer of the R / G / B cholesteric liquid crystal for a first preset time, loading of the first low-frequency high-voltage positive and negative pulses is stopped; loading a second low-frequency high-voltage positive and negative pulse to a strip electrode of a row electrode layer of the R / G / B cholesteric liquid crystal, and simultaneously respectively applying a second low-frequency high-voltage positive and negative pulse with the same frequency and the same voltage amplitude to a strip electrode of a scanning driving column and other column electrodes without scanning driving, and second low-frequency high-voltage positive and negative pulses with the same or different phases. According to the invention, three monochromatic screens of Red, Green and Blue are superposed, driving is carried out in combination with a specific waveform, the mode and the structure are simple, and the driving method is relatively easy to realize.

Description

Technical Field

[0001] The present application relates to the technical field of displays, and in particular to a driving method for a color display screen. Background Art

[0002] In the field of liquid crystal displays (LCDs), cholesteric liquid crystal is one of the mainstream materials and is widely used in electronic products such as LCD TVs, computer monitors, and smartphone screens. It plays an important role in improving display resolution, contrast, and color expression. Existing cholesteric liquid crystals are mostly monochrome displays. The display screen with a three-color structure is relatively complex, and there are also many problems in driving implementation.

[0003] Chinese patent, patent number: CN107728399A discloses a color electronic paper display screen made of cholesteric liquid crystal, including three layers of RGB glass boxes, the three layers of RGB glass boxes are "R" layer glass liquid crystal box A, "G" layer glass liquid crystal box B and "B" layer glass liquid crystal box C, wherein the "B" layer glass liquid crystal box C and the "G" layer glass liquid crystal box B are OC2 double-sided adhesive film, and the "G" layer glass liquid crystal box B and the "R" layer glass liquid crystal box A are OC1 double-sided adhesive film. The "R" layer liquid crystal display box, its structure includes upper I TO glass, lower I TO glass, frame glue and liner, wherein the upper I TO glass and the lower I TO glass are fixed by frame glue and liner. The upper I TO layer is below the upper I TO glass, the lower I TO layer is above the lower I TO glass, and the upper I TO layer and the lower I TO layer are 650 cholesteric liquid crystals between the upper I TO layer and the lower I TO layer, and the wavelength of the cholesteric liquid crystal is 650nm. However, in practical applications, this solution has the problem of large voltage requirement and high cost for driving a three-color display screen. Summary of the invention

[0004] The purpose of the present application is to provide a method for driving a color display screen, so as to solve the problem of inconvenience in driving a cholesteric liquid crystal display screen with a current three-color structure.

[0005] The technical solution of the present invention is: a driving method of a color display screen, the display screen comprises an R-layer glass liquid crystal box, a G-layer glass liquid crystal box, and a B-layer glass liquid crystal box, the R-layer glass liquid crystal box comprises a RED cholesteric liquid crystal, the G-layer glass liquid crystal box comprises a GREED cholesteric liquid crystal, the B-layer glass liquid crystal box comprises a BLUE cholesteric liquid crystal, OC glue is provided between the R-layer glass liquid crystal box and the G-layer glass liquid crystal box, and OC glue is provided between the G-layer glass liquid crystal box and the B-layer glass liquid crystal box;

[0006] The upper layer of the RED cholesteric liquid crystal is an upper I TO layer and an upper glass in sequence, and the lower layer of the RED cholesteric liquid crystal is a lower I TO layer and a lower glass in sequence. The RED cholesteric liquid crystal, the GREED cholesteric liquid crystal and the BLUE cholesteric liquid crystal respectively have strip electrodes of a row electrode layer and strip electrodes of a column electrode layer, and the strip electrodes of the row electrode layer and the strip electrodes of the column electrode layer are connected to a driver through conductive lines.

[0007] The method comprises the following steps:

[0008] Step 1. After a pair of first low-frequency high-voltage positive and negative pulses with the same frequency, the same voltage amplitude and opposite phases are loaded onto the strip electrodes of the row electrodes and the strip electrodes of the column electrode layer of the RED cholesteric liquid crystal, the GREED cholesteric liquid crystal and the BLUE cholesteric liquid crystal for a first preset time, the loading of the first low-frequency high-voltage positive and negative pulses is stopped;

[0009] Step 2. While loading the second low-frequency, high-voltage positive and negative pulses to the strip electrodes of the row electrode layers of the RED cholesteric liquid crystal, the GREED cholesteric liquid crystal and the BLUE cholesteric liquid crystal, second low-frequency, high-voltage positive and negative pulses having the same frequency, the same voltage amplitude, and the same or different phase as the second low-frequency, high-voltage positive and negative pulses are applied to the strip electrodes of the scan-driven columns and other column electrodes that are not scanned and driven.

[0010] Preferably, the step 2 is specifically:

[0011] Step 21. After loading the second low-frequency high-voltage positive and negative pulses with the same frequency, voltage amplitude and phase onto the strip electrodes of the row electrode layers of the RED cholesteric liquid crystal, the GREED cholesteric liquid crystal and the BLUE cholesteric liquid crystal and the strip electrodes of the scan drive columns for a second preset time, stop loading the second low-frequency high-voltage positive and negative pulses;

[0012] Step 22. After applying the second low-frequency high-voltage positive and negative pulses with the same frequency, the same voltage amplitude and the opposite phase to the other column electrodes not scanned and driven for the second preset time, stop applying the second low-frequency high-voltage positive and negative pulses;

[0013] Step 23. Repeat steps 21 and 22 at least once.

[0014] Preferably, the frequency of the first low-frequency, high-voltage positive and negative pulses is greater than or equal to 100 Hz and less than or equal to 1000 Hz, the amplitude of the low-frequency, high-voltage positive and negative pulses is greater than or equal to 20 V and less than or equal to 40 V, the number of pulse pairs loaded with the first low-frequency, high-voltage positive and negative pulses is greater than or equal to 1 and less than or equal to 20, and the time for stopping loading the first low-frequency, high-voltage positive and negative pulses is greater than or equal to 10 ms and less than or equal to 1000 ms.

[0015] Preferably, the frequency of the second low-frequency high-voltage positive and negative pulses is greater than or equal to 500 Hz and less than or equal to 4000 Hz, the amplitude of the low-frequency high-voltage positive and negative pulses is greater than or equal to 10 V and less than or equal to 18 V, the number of pulse pairs loaded with the second low-frequency high-voltage positive and negative pulses is greater than or equal to 1 and less than or equal to 20, and the time for stopping loading the second low-frequency high-voltage positive and negative pulses is greater than or equal to 1 ms and less than or equal to 10 ms.

[0016] Preferably, the driver includes a control unit, an interface unit, a temperature detection unit, a pressure detection unit, a graphic storage unit, a voltage generation unit, a waveform generation unit and a timer.

[0017] Compared with the prior art, the advantages of the present application are: the present invention mainly superimposes three monochrome screens of Red, Green and Blue on the basis of a monochrome cholesteric liquid crystal display screen, and then drives the screen in combination with a driver that generates a specific waveform. In this way, not only is the STN method simple in structure, but the driving method is also relatively easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present application is further described below in conjunction with the accompanying drawings and embodiments:

[0019] Figure 1 A schematic diagram of the structure of a display screen of a driving method of a color display screen of the present application;

[0020] Figure 2 A schematic diagram of a row electrode layer and a column electrode layer of a driving method for a color display screen of the present application;

[0021] Figure 3 This is a schematic structural diagram of a driver for a driving method of a color display screen in the present application;

[0022] Figure 4 This is a schematic diagram of an image clearing process of a driving method for a color display screen of the present application;

[0023] Figure 5 This is a schematic diagram of an image clearing pulse waveform of a driving method for a color display screen of the present application;

[0024] Figure 6 A schematic diagram showing a graphical flow of a driving method for a color display screen of the present application;

[0025] Figure 7 A schematic diagram of a pulse waveform is shown in a driving method of a color display screen of the present application.

[0026] in:

[0027] 1. Upper glass, 2. Upper I TO layer, 3. RED cholesteric liquid crystal, 4. Lower I TO layer, 5. Lower glass, 6. OC glue, 7. GREED cholesteric liquid crystal, 8. BLUE cholesteric liquid crystal, 9. Conductive wire, 10. Driver, 11. Strip electrodes of row electrode layer, 12. Strip electrodes of column electrode layer. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present application clearer, the embodiments of the present application will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiment is only one embodiment of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0029] "Embodiment" referred to herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present application. In the description of the embodiment of the present application, it should be understood that the terms "first", "second" and "third" etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second" and "third" etc. may include one or more of the features explicitly or implicitly. Moreover, the terms "first", "second" and "third" etc. are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiment of the present application described here can be implemented in an order other than illustrated or described here. In addition, the terms "including" and "for" and any of their variations are intended to cover non-exclusive inclusions.

[0030] like Figure 1-2 As shown, this embodiment provides a driving method for a color display screen, the display screen comprises an R-layer glass liquid crystal box, a G-layer glass liquid crystal box, and a B-layer glass liquid crystal box, the R-layer glass liquid crystal box comprises a RED cholesteric liquid crystal 3, the G-layer glass liquid crystal box comprises a GREED cholesteric liquid crystal 7, the B-layer glass liquid crystal box comprises a BLUE cholesteric liquid crystal 8, an OC glue (6) is provided between the R-layer glass liquid crystal box and the G-layer glass liquid crystal box, and an OC glue (6) is provided between the G-layer glass liquid crystal box and the B-layer glass liquid crystal box;

[0031] The upper layer of the RED cholesteric liquid crystal 3 is the upper I TO layer 2 and the upper glass 1 in sequence, and the lower layer of the RED cholesteric liquid crystal 3 is the lower I TO layer 4 and the lower glass 5 in sequence. The RED cholesteric liquid crystal 3, the GREED cholesteric liquid crystal 7 and the BLUE cholesteric liquid crystal 8 respectively have strip electrodes 11 of the row electrode layer and the strip electrodes 12 of the column electrode layer. The strip electrodes 11 of the row electrode layer and the strip electrodes 12 of the column electrode layer are connected to the driver 10 through conductive wires 9. Each layer of the display screen has an STN structure and the resolution is the same. It should be noted here that the cholesteric liquid crystal display screen is a well-known electronic display device in the art, so its specific structure is not described in detail here.

[0032] like Figure 3 As shown, in this embodiment, the driver 10 includes a control unit, an interface unit, a temperature detection unit, a pressure detection unit, a graphic storage unit, a voltage generation unit, a waveform generation unit and a timer.

[0033] like Figure 4 As shown, in this embodiment, in the method of driving a color display screen, the image on the display screen is first cleared. In the clearing method, all row electrodes and all column electrodes in R / G / B need to be selected, and then waveform output is performed. The waveform is as shown in FIG. Figure 5 As shown, the waveform output method includes: after a first preset time, a pair of first low-frequency high-voltage positive and negative pulses with the same frequency, the same voltage amplitude and opposite phases are respectively loaded onto the strip electrodes of the row electrodes and the strip electrodes of the column electrode layer of the RED cholesteric liquid crystal 3, the GREED cholesteric liquid crystal 7 and the BLUE cholesteric liquid crystal 8, and then the loading of the first low-frequency high-voltage positive and negative pulses is stopped. At this time, the strip electrodes 11 of the row electrode layer and the strip electrodes 12 of the column electrode layer are powered off.

[0034] Then the first low-frequency high-voltage positive and negative pulses are repeatedly loaded onto the strip electrodes of the row electrodes and the strip electrodes of the column electrode layer of the RED cholesteric liquid crystal 3, GREED cholesteric liquid crystal 7 and BLUE cholesteric liquid crystal 8 for at least 2 times. In practical applications, it can be up to 20 times, and the interval between each time is greater than or equal to 10ms and less than or equal to 1000ms. The frequency of the first low-frequency high-voltage positive and negative pulses is greater than or equal to 100Hz and less than or equal to 1000Hz, and the amplitude of the low-frequency high-voltage positive and negative pulses is greater than or equal to 20V and less than or equal to 40V.

[0035] like Figure 6 As shown, in this embodiment, the process of driving the color display screen to display graphics includes sequentially reading the strip electrodes 11 of all row electrode layers in R / G / B and selecting them, and identifying the corresponding states of the strip electrodes 12 of all column electrode layers in the current R / G / B, and then outputting waveforms. The waveforms are shown in FIG. Figure 7 As shown, the waveform output modes include:

[0036] While loading the second low-frequency, high-voltage positive and negative pulses onto the strip electrodes of the row electrode layers of the RED cholesteric liquid crystal, the GREED cholesteric liquid crystal and the BLUE cholesteric liquid crystal, second low-frequency, high-voltage positive and negative pulses having the same frequency, the same voltage amplitude, and the same or different phase as the second low-frequency, high-voltage positive and negative pulses are applied to the strip electrodes of the scan-driven columns and other column electrodes that are not scan-driven.

[0037] The step 2 is specifically as follows:

[0038] Step 21. After loading the second low-frequency high-voltage positive and negative pulses with the same frequency, voltage amplitude and phase onto the strip electrodes of the row electrode layers of the RED cholesteric liquid crystal, the GREED cholesteric liquid crystal and the BLUE cholesteric liquid crystal and the strip electrodes of the scan drive columns for a second preset time, stop loading the second low-frequency high-voltage positive and negative pulses;

[0039] Step 22. After applying the second low-frequency high-voltage positive and negative pulses with the same frequency, the same voltage amplitude and the opposite phase to the other column electrodes not scanned and driven for the second preset time, stop applying the second low-frequency high-voltage positive and negative pulses;

[0040] Step 23. Repeat step 21 and step 22 at least once. In practical applications, the number of times can be up to 20. The repetition interval is greater than or equal to 1ms and less than or equal to 10ms.

[0041] Among them, the frequency of the second low-frequency high-voltage positive and negative pulses is greater than or equal to 500Hz and less than or equal to 4000Hz, and the amplitude of the low-frequency high-voltage positive and negative pulses is greater than or equal to 10V and less than or equal to 18V.

[0042] The above embodiments are only for illustrating the technical concept and features of the present application, and their purpose is to enable people familiar with this technology to understand the content of the present application and implement it accordingly, and they cannot be used to limit the scope of protection of the present application. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or basic features of the present application. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present application is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present application.

Claims

1. A method for driving a color display screen, characterized in that: The display screen comprises an R-layer glass liquid crystal box, a G-layer glass liquid crystal box, and a B-layer glass liquid crystal box, wherein the R-layer glass liquid crystal box comprises RED cholesteric liquid crystal (3), the G-layer glass liquid crystal box comprises GREED cholesteric liquid crystal (7), and the B-layer glass liquid crystal box comprises BLUE cholesteric liquid crystal (8), and OC glue (6) is provided between the R-layer glass liquid crystal box and the G-layer glass liquid crystal box, and between the G-layer glass liquid crystal box and the B-layer glass liquid crystal box. The upper layer of the RED cholesteric liquid crystal (3) is an upper ITO layer (2) and an upper glass (1) in sequence, and the lower layer of the RED cholesteric liquid crystal (3) is a lower ITO layer (4) and a lower glass (5) in sequence. The RED cholesteric liquid crystal (3), the GREED cholesteric liquid crystal (7) and the BLUE cholesteric liquid crystal (8) are respectively provided with strip electrodes (11) of a row electrode layer and strip electrodes (12) of a column electrode layer. The strip electrodes (11) of the row electrode layer and the strip electrodes (12) of the column electrode layer are connected to a driver (10) via conductive wires (9); The method comprises the following steps: Step 1. After a first preset time, a pair of first low-frequency high-voltage positive and negative pulses with the same frequency, the same voltage amplitude and opposite phases are respectively loaded onto the strip electrodes of the row electrodes and the strip electrodes of the column electrode layer of the RED cholesteric liquid crystal (3), the GREED cholesteric liquid crystal (7) and the BLUE cholesteric liquid crystal (8), and then the loading of the first low-frequency high-voltage positive and negative pulses is stopped; Step 2. While loading the second low-frequency high-voltage positive and negative pulses onto the strip electrodes of the row electrode layers of the RED cholesteric liquid crystal (3), the GREED cholesteric liquid crystal (7) and the BLUE cholesteric liquid crystal (8), second low-frequency high-voltage positive and negative pulses having the same frequency, the same voltage amplitude, and the same or different phase as the second low-frequency high-voltage positive and negative pulses are applied to the strip electrodes of the scan-driven columns and other column electrodes that are not scan-driven.

2. A method for driving a color display screen according to claim 1, characterized in that: The step 2 is specifically as follows: Step 21. After loading the second low-frequency high-voltage positive and negative pulses with the same frequency, voltage amplitude and phase onto the strip electrodes of the row electrode layers of the RED cholesteric liquid crystal (3), the GREED cholesteric liquid crystal (7) and the BLUE cholesteric liquid crystal (8) and the strip electrodes of the scan drive columns for a second preset time, stop loading the second low-frequency high-voltage positive and negative pulses; Step 22. After applying the second low-frequency high-voltage positive and negative pulses with the same frequency, the same voltage amplitude and the opposite phase to the other column electrodes not scanned and driven for the second preset time, stop applying the second low-frequency high-voltage positive and negative pulses; Step 23. Repeat steps 21 and 22 at least once.

3. A method for driving a color display screen according to claim 2, characterized in that: The frequency of the first low-frequency high-voltage positive and negative pulses is greater than or equal to 100 Hz and less than or equal to 1000 Hz, the amplitude of the low-frequency high-voltage positive and negative pulses is greater than or equal to 20 V and less than or equal to 40 V, the number of pulse pairs loaded with the first low-frequency high-voltage positive and negative pulses is greater than or equal to 1 and less than or equal to 20, and the time for stopping loading the first low-frequency high-voltage positive and negative pulses is greater than or equal to 10 ms and less than or equal to 1000 ms.

4. A method for driving a color display screen according to claim 3, characterized in that: The frequency of the second low-frequency high-voltage positive and negative pulses is greater than or equal to 500 Hz and less than or equal to 4000 Hz, the amplitude of the low-frequency high-voltage positive and negative pulses is greater than or equal to 10 V and less than or equal to 18 V, the number of pulse pairs loaded with the second low-frequency high-voltage positive and negative pulses is greater than or equal to 1 and less than or equal to 20, and the time to stop loading the second low-frequency high-voltage positive and negative pulses is greater than or equal to 1 ms and less than or equal to 10 ms.

5. A method for driving a color display screen according to claim 4, characterized in that: The driver (10) comprises a control unit, an interface unit, a temperature detection unit, a pressure detection unit, a graphic storage unit, a voltage generation unit, a waveform generation unit and a timer.

Images