A system and method for extending the color development time of an electrochromic screen

Abstract

The present invention discloses a system and method for extending the color development time of an electrochromic screen, comprising: the transistor drain of each row of pixels is connected to a data-end screen control module through a first switch circuit; the transistor gate of each column of pixels is connected to a scan-end screen control module through a second switch circuit; the color development unit of each pixel is grounded through a third switch circuit; the first switch circuit, the second switch circuit, and the third switch circuit are all connected to a switch circuit control module, and the switch circuit control module can control each switch circuit to be disconnected when the screen is in a static mode; and control each switch circuit to be connected when the screen is in a refresh mode. When the screen is in a static state, the present invention disconnects the connection between the transistor drain and the gate and the external circuit through a switch circuit, thereby cutting off the leakage current, and does not need to continuously refresh the screen, and can greatly extend the color development time under low power consumption conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochromic screen control, and in particular to a system and method for prolonging the color development time of an electrochromic screen. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] A type of electrochromic pixel that constitutes the screen, its basic structure includes a triode and a color display unit, the gate of the triode is connected to the scanning end, the drain of the triode is connected to the data end, and the source of the triode is connected to the color display unit; one end of the color display unit is connected to the source, and the other end is grounded; the gates of the triodes of each column of pixels on the screen are connected together, and their voltage input is controlled by the screen control module. The drains of the triodes of each row of pixels on the screen are connected together to form the data end, and their voltage input is also controlled by the screen control module. By coordinating the control of the input voltage of the gate and drain of the triode, the control of the current passing through the color display unit is achieved, and then the control of the color change of the electrochromic pixel is achieved.

[0004] In order to prepare screens over a large area, there is a type of process that uses printing to prepare a large number of triodes and color display unit circuits, but in this context, it is difficult to control the leakage current of large-scale triode circuits. The color display unit has capacitive characteristics, and the presence of leakage current will cause the charge on the color display unit to slowly drain away, resulting in a non-ideal condition where the pixel gradually changes color. This fading phenomenon is not obvious in a short period of time, but when the screen needs to display the same image for a long time, in order to prevent the screen from fading due to leakage current, the traditional solution is to refresh the screen regularly, but this method will result in greater power consumption. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a system and method for prolonging the color display time of an electrochromic screen. By adding an external circuit and a control module, the gate leakage current and the drain-source leakage current can be suppressed without frequently refreshing the screen, thereby suppressing the fading of the display screen under low power consumption conditions.

[0006] In some embodiments, the following technical solutions are adopted:

[0007] A system for extending the color development time of an electrochromic screen, characterized by comprising:

[0008] The transistor drain of each row of pixels is connected to the data end screen control module through the first switch circuit; the transistor gate of each column of pixels is connected to the scanning end screen control module through the second switch circuit; the color display unit of each pixel is grounded through the third switch circuit;

[0009] The first switch circuit, the second switch circuit and the third switch circuit are all connected to a switch circuit control module, and the switch circuit control module can control each switch circuit to be disconnected when the screen is in a static mode; and control each switch circuit to be connected when the screen is in a refresh mode.

[0010] As an optional implementation, the first switching circuit is a triode, the drain of the triode is connected to the drain of the triode in the pixel, the source of the triode is connected to the data-end level conversion module, and the gate of the triode is connected to the data-end screen control module; the data-end level conversion module is connected to the data-end screen control module; a high level or a low level is applied to the gate of the triode through the data-end screen control module to control the on and off of the triode.

[0011] As an optional implementation, the second switching circuit is a transistor, the drain of the transistor is connected to the gate of the transistor in the pixel, the source of the transistor is connected to the scanning end level conversion module, and the gate of the transistor is connected to the scanning end screen control module; a high level or a low level is applied to the gate of the transistor through the scanning end screen control module to control the on and off of the transistor.

[0012] As an optional implementation, the third switching circuit is a transistor, the source of the transistor is connected to the color display unit, the source and gate of the transistor are directly connected to the data-end screen control module, wherein the source is connected to the ground wire in the data-end screen control module; a high level or a low level is applied to the gate of the transistor through the data-end screen control module to control the on and off of the transistor.

[0013] As an optional implementation, the first switch circuit, the second switch circuit or the third switch circuit is an analog switch.

[0014] As an optional implementation, the switch circuit control module includes:

[0015] A timer unit, used to control the time intervals of on and off of each switch circuit;

[0016] The timing control unit is used to control the on and off of each switch circuit according to the set timing.

[0017] In other embodiments, the following technical solutions are adopted:

[0018] A method for extending the color development time of an electrochromic screen, based on the above system, comprises:

[0019] When the screen changes from the refresh mode to the static mode, each switch circuit is controlled to be disconnected according to the set timing;

[0020] When the screen changes from the static mode to the refresh mode, each switch circuit is controlled to be turned on according to the set timing.

[0021] As an optional implementation, when the screen changes from refresh mode to static mode, the first switch circuit is first controlled to be turned off, and after a set time, the second switch circuit is controlled to be turned off; after another set time, the third switch circuit is controlled to be turned off.

[0022] As an optional implementation, when the screen changes from static mode to refresh mode, the third switch circuit is first controlled to be turned on, and after a set time, the second switch circuit is controlled to be turned on; after another set time, the first switch circuit is controlled to be turned on.

[0023] In other embodiments, the following technical solutions are adopted:

[0024] An electrochromic screen comprises the above-mentioned system for prolonging the color development time of the electrochromic screen.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) When the screen is in a stationary state, the present invention disconnects the connection between the drain and gate of the transistor and the external circuit through a switching circuit, thereby cutting off the leakage current. There is no need to continuously refresh the screen, and the color display time can be greatly extended under low power consumption conditions.

[0027] (2) The circuit structure of the present invention is simple and easy to implement; the timing control part of each switch circuit can realize the switching between the refresh state and the static state, and can be adapted by adjusting the control program, and has good modifiability.

[0028] Other features and advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the overall structure of a system for extending the color development time of an electrochromic screen in an embodiment of the present invention;

[0030] Figure 2 is a schematic diagram of the connection relationship of transistors in a pixel in an embodiment of the present invention;

[0031] Figure 3 is a schematic diagram of the connection of a switch circuit in an embodiment of the present invention;

[0032] Figure 4 Schematic diagram of control timing of each switch circuit in an embodiment of the present invention;

[0033] Figure 5This is a flow chart of a method for prolonging the color development time of an electrochromic screen in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0035] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0036] Embodiment 1

[0037] In an electrochromic screen, each electrochromic pixel includes: a triode and a color display unit, the gate of the triode is connected to the scanning end, the drain of the triode is connected to the data end, and the source of the triode is connected to the color display unit. The data end screen control module and the scanning end screen control module can provide a set voltage input to the triode in the pixel, thereby applying a set current to the color display unit, thereby realizing the color change control of the electrochromic pixel.

[0038] The color display unit that constitutes the electrochromic pixel has a capacitive characteristic. The source current is applied through the transistor in the electrochromic pixel, and the color display operation is performed through the color display unit, which is equivalent to the process of charging the capacitor. When the gate and drain of the transistor of the electrochromic unit are at a low level for a long time, the transistor is in the cut-off region. Under ideal conditions, the charge of the color display unit will not be lost, but there is a weak leakage current in the gate and drain of the transistor. After a long time, the charge in the color display unit is significantly reduced, causing the screen to fade.

[0039] Based on this, in one or more embodiments, a system for extending the color development time of an electrochromic screen is disclosed, combined with Figure 1 and Figure 2 , including:

[0040] The transistor drain of each row of pixels is connected to the data end screen control module through the first switch circuit; the transistor gate of each column of pixels is connected to the scanning end screen control module through the second switch circuit; the color display unit of each pixel is grounded through the third switch circuit; the first switch circuit, the second switch circuit and the third switch circuit are all connected to the switch circuit control module, and the switch circuit control module can control each switch circuit to be disconnected when the screen is in the static mode; and control each switch circuit to be connected when the screen is in the refresh mode.

[0041] It is easy for those skilled in the art to understand that the above-mentioned rows and columns are interchangeable, which does not constitute a limitation on the protection scope of the present invention; in addition, the data end screen control module and the scanning end screen control module can be set as two independent modules respectively, or can be set as one module to respectively realize the functions of the data end screen control module and the scanning end screen control module.

[0042] In some implementations, the first switch circuit, the second switch circuit, or the third switch circuit may use an analog switch, such as a CD4066 chip.

[0043] In other embodiments, the first switch circuit, the second switch circuit or the third switch circuit may use a transistor; specifically, in combination with Figure 3 When the first switch circuit uses a triode, the drain of the triode is connected to the drain of the triode in the pixel, and the source of the triode is connected to the data-end level conversion module, which is connected to the data-end screen control module. Because the signal from the screen control module is a digital signal, the high level and low level of its output may not meet the requirements of the electrochromic module, so it is necessary to use a level conversion module to convert it to the level required by the electrochromic module. The gate of the triode is directly connected to the data-end screen control module. When the screen is in refresh mode, the data-end screen control module applies a high level to the gate of the triode, and the triode is turned on. When the screen is in static mode, the data-end screen control module applies a low level to the gate of the triode, and the triode is turned off.

[0044] When the second switching circuit uses a transistor, the drain of the transistor is connected to the gate of the transistor in the pixel, the source of the transistor is connected to the scanning end level conversion module, the scanning end level conversion module is connected to the scanning end screen control module, and the working principle is the same as the data end; the gate of the transistor is directly connected to the scanning end screen control module; when the screen is in refresh mode, the scanning end screen control module applies a high level to the gate of the transistor, and the transistor is turned on; when the screen is in static mode, the scanning end screen control module applies a low level to the gate of the transistor, and the transistor is turned off.

[0045] When the third switch circuit uses a triode, the source of the triode is connected to the color display unit, and the source and gate of the triode are directly connected to the data end screen control module, wherein the source is connected to the ground wire inside the data end screen control module, which is equivalent to grounding, and the gate is controlled by the data end screen control module. When the screen is in refresh mode, the data end screen control module applies a high level to the gate of the triode, and the triode is turned on. When the screen is in static mode, the data end screen control module applies a low level to the gate of the triode, and the triode is turned off.

[0046] In this embodiment, the switch circuit control module includes: a timer unit and a timing control unit; wherein the timer unit is used to control the time interval of each switch circuit being turned on and off; the timing control unit is used to control the on and off of each switch circuit according to the set timing; specifically, when the screen changes from the refresh mode to the static mode, the first switch circuit is first controlled to be turned off, and after a set time, the second switch circuit is controlled to be turned off; after a set time, the third switch circuit is controlled to be turned off; and when the screen changes from the static mode to the refresh mode, the third switch circuit is first controlled to be turned on, and after a set time, the second switch circuit is controlled to be turned on; after a set time, the first switch circuit is controlled to be turned on. The timing control method of this embodiment can be implemented using FPGA, single-chip microcomputer or customized digital chip. It has good modifiability. For different types of electrochromic pixels, the various time parameters required may be different. Under the timing control method, it can be adapted by adjusting the control program. And it has high compatibility and can be easily controlled by other digital circuits.

[0047] In this embodiment, for the manufacture of the electrochromic screen, the screen and the switching circuit can be manufactured together by using a screen printing process, wherein the pin of the screen is connected to one end of the switching circuit, and the other end of the switching circuit and the control end are connected to a driving module composed of a screen control module and a switching circuit control module, so as to realize the control of the screen.

[0048] In the control of the screen, there are refresh mode and static mode. First, input the content to be displayed to the screen control module, turn on the screen, and the system enters the refresh mode by default.

[0049] In the refresh mode, each switch circuit of the embodiment remains connected, the gate of the triode in the electrochromic pixel is connected to the scanning end screen control module, and the drain of the triode is connected to the data end screen control module; the screen control module controls the scanning end and the data end level conversion module to generate a specific electrical signal at the gate and drain of the triode in the electrochromic pixel through the first switch circuit and the second switch circuit. In this way, the continuous refresh of the pattern on the screen is realized; under the drive of the screen control module, the screen can display the pictures in sequence according to the established settings.

[0050] When the screen needs to display a single picture, it enters the static mode. Under the control of the switching circuit control module, each switching circuit is disconnected, the connection between the transistor drain and the gate and the external circuit is cut off, the leakage current of the electrochromic pixel is cut off, and the charge in the color display unit is difficult to flow out, so the color can remain unchanged for a long time, and maintaining this static state does not require a large power consumption.

[0051] The system circuit structure of this embodiment is simple, and can be attached to the screen control module or the switch circuit control module, and can be conveniently manufactured together with the screen control module or the switch circuit control module. Similarly, the switch circuit control module can also be attached to the screen control module, and does not need to be manufactured separately.

[0052] After experimental verification, under the condition of 25℃, the leakage current is 10pA when each switch circuit is closed. For the electrochromic screen, under normal coloring, its charge is 10uC, and the time required for 50% of the charge to be lost through the leakage current of the switch circuit is 10^6 seconds, which is about 277.8 hours. This means that suppressing the charge loss of the electrochromic screen through the switch circuit can effectively extend the coloring time.

[0053] In addition, the system of this embodiment has a more obvious effect on reducing the power consumption of the electrochromic screen in a static state. Assuming that the screen working time is t, and the static state time is t s , the power to maintain the refresh state is P re , the power to maintain the static state, that is, the power to keep the switch circuit off is P keep , then the ratio of the power of the display screen in the system of this embodiment to the power of the display screen in the traditional solution is:

[0054]

[0055] Because P keep << re , so when the screen is stationary half of the time, the power savings are close to 50% compared to traditional methods.

[0056] Embodiment 2

[0057] In one or more embodiments, a method for extending the color development time of an electrochromic screen is disclosed. The method is based on the system described in Example 1 and specifically includes the following process:

[0058] Combination Figure 4 and Figure 5 When the screen changes from refresh mode to static mode, each switch circuit is controlled to be disconnected according to the set timing; specifically: first the first switch circuit is controlled to be turned off, and after a set time, the second switch circuit is controlled to be turned off; after another set time, the third switch circuit is controlled to be turned off.

[0059] When the screen changes from static mode to refresh mode, each switch circuit is controlled to be turned on according to the set timing, specifically: first, the third switch circuit is controlled to be turned on, and the transistor gate voltage changes from a low level to a high level. After a set time, the second switch circuit is controlled to be turned on; after another set time, the first switch circuit is controlled to be turned on.

[0060] Combination Figure 4 , the timing control part of this embodiment can realize that when the refresh state is changed to the static state, the first switch circuit first changes from a high level to a low level, then the second switch circuit changes from a high level to a low level, and finally the third switch circuit changes from a high level to a low level. When the static state is changed to the refresh state, the third switch circuit first changes from a low level to a high level, then the second switch circuit changes from a low level to a high level, and finally the third switch circuit changes from a low level to a high level. Limited by the characteristics of the electrochromic pixel, the time interval of the jump of the first, second, and third switch circuits should not be less than 2ms. This embodiment uses a 1ms clock for control.

[0061] It should be noted that the specific implementation process of the above method has been described in detail in Example 1 and will not be described in detail here.

[0062] Embodiment 3

[0063] In one or more embodiments, an electrochromic screen is disclosed, which includes the system for prolonging the color development time of the electrochromic screen described in Example 1.

[0064] The electrochromic screen of this embodiment can be applied to a dot matrix screen composed of electrochromic pixels, a segment code screen or a single pixel screen with a fixed image, etc. It has high flexibility and a wide range of applications.

[0065] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A system for extending the color development time of an electrochromic screen, characterized in that: include: The drain of the transistor of each row of pixels is connected to the data end screen control module through the first switch circuit; The transistor gate of each column of pixels is connected to the scanning end screen control module through the second switch circuit; The color display unit of each pixel is grounded via a third switch circuit; The first switch circuit, the second switch circuit and the third switch circuit are all connected to a switch circuit control module, and the switch circuit control module can control each switch circuit to be disconnected when the screen is in a static mode; and control each switch circuit to be connected when the screen is in a refresh mode; Based on the system, a method for extending the color development time of an electrochromic screen is implemented, comprising: When the screen changes from the refresh mode to the static mode, each switch circuit is controlled to be disconnected according to the set timing; When the screen changes from the static mode to the refresh mode, each switch circuit is controlled to be turned on according to the set timing; When the screen changes from the refresh mode to the static mode, the first switch circuit is first controlled to be turned off, and after a set time, the second switch circuit is controlled to be turned off; after another set time, the third switch circuit is controlled to be turned off.

2. A system for extending the color development time of an electrochromic screen as claimed in claim 1, characterized in that: The first switching circuit is a transistor, the drain of the transistor is connected to the drain of the transistor in the pixel, the source of the transistor is connected to the data end level conversion module, and the gate of the transistor is connected to the data end screen control module; the data end level conversion module is connected to the data end screen control module; a high level or a low level is applied to the gate of the transistor through the data end screen control module to control the on and off of the transistor.

3. A system for extending the color development time of an electrochromic screen as claimed in claim 1, characterized in that: The second switching circuit is a transistor, the drain of the transistor is connected to the gate of the transistor in the pixel, the source of the transistor is connected to the scanning end level conversion module, and the gate of the transistor is connected to the scanning end screen control module; a high level or a low level is applied to the gate of the transistor through the scanning end screen control module to control the on and off of the transistor.

4. A system for extending the color development time of an electrochromic screen as claimed in claim 1, characterized in that: The third switching circuit is a transistor, the source of which is connected to the color display unit, and the source and gate of the transistor are directly connected to the data-end screen control module, wherein the source is connected to the ground wire in the data-end screen control module; a high level or a low level is applied to the gate of the transistor through the data-end screen control module to control the on and off of the transistor.

5. A system for extending the color development time of an electrochromic screen as claimed in claim 1, characterized in that: The first switch circuit, the second switch circuit or the third switch circuit is an analog switch.

6. A system for extending the color development time of an electrochromic screen as claimed in claim 1, characterized in that: The switch circuit control module comprises: A timer unit, used to control the time intervals of on and off of each switch circuit; The timing control unit is used to control the on and off of each switch circuit according to the set timing.

7. A system for extending the color development time of an electrochromic screen as claimed in claim 1, characterized in that: When the screen changes from the static mode to the refresh mode, the third switch circuit is first controlled to be turned on, and after a set time, the second switch circuit is controlled to be turned on; after another set time, the first switch circuit is controlled to be turned on.

8. An electrochromic screen, characterized in that: A system for prolonging the color development time of an electrochromic screen comprising the system described in any one of claims 1-7.

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