Electronic paper and driving module thereof

Abstract

The present invention discloses an electronic paper and its driving module, comprising: a main driving port for outputting a periodic voltage sequence; a parallel branch group comprising n branches, one end of each branch being connected to the main driving port and the other end being connected to the cholesteric liquid crystal layer of the electronic paper module via an AC common-level wiring; an adjustment resistor unit comprising m groups of adjustment resistors, one group of adjustment resistors being connected in series between any two of the n branches, where n ≥ 4 and m ≥ 2; and an impedance balancing logic unit for configuring the resistance values ​​of the m groups of adjustment resistors according to the wiring resistance values ​​of each branch, so that the total impedance of all branches is equal. The electronic paper driving module of the present application compensates for the uneven current distribution caused by the wiring resistance differences by connecting differentiated adjustment resistors in series in different branches, making the total impedance of all branches equal, thereby balancing the charge and discharge currents and avoiding the problem of device burning caused by local overcurrent in high-temperature environments.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to an electronic paper and a driving module thereof. Background Art

[0002] Cholesteric liquid crystals are widely used in electronic paper display technology due to their bistable properties. Figure 1-Figure 3 As shown in the figure, the existing active drive solution applies a periodic voltage (+ common voltage → 0 → - common voltage → 0V) to the liquid crystal layer through the AC common-level wiring on the color filter substrate side. However, in large-size modules, as the panel size increases, the uneven distribution of the AC common-level wiring resistance leads to significant differences in charge and discharge currents, such as Figure 4 As shown in the figure, it is a conventional AC common-level design. The gradient distribution of the AC common-level wiring resistance is low on both sides and high in the middle, which leads to serious uneven charging and discharging currents. Figure 5 and Figure 6 As shown, the edge trace current is as high as 5A, while the center trace current is less than 1A. This current imbalance can cause the binding pins to burn out due to local overcurrent. When the current in the middle branch is too low, the LCD response speed is affected. The high current area accelerates aging at high temperatures, causing the screen to fail. Summary of the Invention

[0003] In order to solve the technical problems existing in the background technology, the present invention proposes an electronic paper driving module.

[0004] In a first aspect, the present invention provides an electronic paper driving module, comprising:

[0005] The main driving port is used to output a periodic voltage sequence;

[0006] A parallel branch group includes n branches, one end of each branch is connected to the main driving port, and the other end is connected to the cholesteric liquid crystal layer of the electronic paper module through an AC common-level terminal wiring;

[0007] The regulating resistor unit includes m groups of regulating resistors, and a group of regulating resistors is connected in series between any two branches in the n branches, where n ≥ 4 and m ≥ 2;

[0008] The impedance balancing logic unit is used to configure the resistance values ​​of the m groups of regulating resistors according to the wiring resistance value of each branch so as to make the total impedance of all branches equal.

[0009] Preferably, a set of regulating resistors is connected in series between any two of the n branches, specifically:

[0010] The n branches are arranged from top to bottom based on the position of the main drive port. Each branch corresponds to a group of regulating resistors connected in series, where:

[0011] The first branch and the nth branch are connected in series with a first regulating resistor R1;

[0012] The second branch and the (n-1)th branch are connected in series with a second regulating resistor R2;

[0013] The third branch and the (n-2)th branch are connected in series with a third regulating resistor R3;

[0014] Similarly, the kth branch and the (n-k+1)th branch are connected in series with the kth regulating resistor Rk, where k=1, 2,…, m.

[0015] Preferably, the resistance values ​​corresponding to the m groups of regulating resistors decrease from both sides to the middle according to the corresponding branch positions.

[0016] Preferably, when the n branches are specifically six branches, the first branch and the sixth branch are connected in series with the first regulating resistor R1, the second branch and the fifth branch are connected in series with the second regulating resistor R2; the third branch and the fourth branch are connected in series with the third regulating resistor R3, wherein the resistance relationship among the first regulating resistor R1, the second regulating resistor R2 and the third regulating resistor R3 satisfies R1>R2>R3.

[0017] Preferably, the resistance configuration of each group of regulating resistors in the regulating resistor unit satisfies: ;

[0018] in, is the total resistance value of any branch among the n branches; is the wiring resistance value of any branch among the n branches; is the resistance of the regulating resistor corresponding to any one of the n branches.

[0019] Preferably, the impedance balancing logic unit includes:

[0020] A data acquisition module is used to obtain the wiring resistance value of each of the n branches through simulation modeling or actual measurement;

[0021] The compensation calculation module calculates the corresponding compensation resistance value, that is, the resistance value of the adjustment resistor, according to the wiring resistance value.

[0022] Preferably, the application timing of the periodic voltage sequence is:

[0023] The first stage t1: applying a positive common voltage for a duration of t1 to drive the liquid crystal molecules to switch to the H state;

[0024] The second stage t2: drops to 0V, lasts for t2, and stabilizes the electric field distribution;

[0025] The third stage t3: applying a negative common voltage for a duration of t3 to drive the liquid crystal molecules to switch to the P state or FC state;

[0026] The fourth stage t4: drops to 0V again, lasting for t4, completing the charge and discharge cycle.

[0027] Preferably, it also includes:

[0028] The dynamic feedback module is used to monitor the current value of each branch in real time and adjust the resistance value according to the current deviation to stabilize the current within the preset range.

[0029] In a second aspect, the present invention provides an electronic paper comprising the electronic paper driving module according to any one of the above items.

[0030] The electronic paper driver module proposed in this invention comprises a master drive port, a parallel branch group, an adjustable resistor unit, and an impedance balancing logic unit. By connecting differentiated adjustable resistors in series in different branches, the module compensates for uneven current distribution caused by varying wiring resistance, ensuring equal total impedance across all branches. This balances charge and discharge currents and avoids device burnout caused by localized overcurrent in high-temperature environments. This invention is suitable for large-scale cholesteric liquid crystal electronic paper modules, significantly improving product reliability and service life.

[0031] The present invention further provides an electronic paper comprising the above-mentioned electronic paper driving module.

[0032] In the present invention, the electronic paper proposed has a technical effect similar to that of the above-mentioned driving module, so it will not be described in detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of a cholesteric electronic paper module;

[0034] Figure 2 Schematic diagram of substrate distribution of cholesteric electronic paper module;

[0035] Figure 3 Schematic diagram of the co-level distribution of the cholesteric electronic paper module;

[0036] Figure 4 Schematic diagram of AC common-stage charging and discharging of cholesteric electronic paper module;

[0037] Figure 5 It is a schematic diagram of the driving structure of the prior art;

[0038] Figure 6 A schematic diagram of current overcharging in the prior art;

[0039] Figure 7 This is a schematic diagram of the six-branch driving structure of an electronic paper driving module proposed by the present invention;

[0040] Figure 8 This is a schematic diagram of the equivalent circuit structure of the six-branch driving structure of the electronic paper driving module proposed by the present invention;

[0041] Figure 9 This is a schematic diagram of the current allocation of six branches of an electronic paper driving module proposed by the present invention;

[0042] Figure 10 This is a schematic diagram of a driving module of an electronic paper driving module proposed in the present invention. DETAILED DESCRIPTION

[0043] Reference Figures 1-10 The present invention provides an electronic paper driving module, comprising:

[0044] The main drive port is used to output a periodic voltage sequence.

[0045] In this embodiment, the application timing of the periodic voltage sequence is:

[0046] The first stage t1: applying a positive common voltage for a duration of t1 to drive the liquid crystal molecules to switch to the H state;

[0047] The second stage t2: drops to 0V, lasts for t2, and stabilizes the electric field distribution;

[0048] The third stage t3: applying a negative common voltage for a duration of t3 to drive the liquid crystal molecules to switch to the P state or FC state;

[0049] The fourth stage t4: drops to 0V again, lasting for t4, completing the charge and discharge cycle.

[0050] The parallel branch group includes n branches, one end of each branch is connected to the main driving port, and the other end is connected to the cholesteric liquid crystal layer of the electronic paper module through an AC common-level wiring.

[0051] The regulating resistor unit includes m groups of regulating resistors. A group of regulating resistors is connected in series between any two branches in the n branches, where n≥4 and m≥2.

[0052] The impedance balancing logic unit is used to configure the resistance values ​​of the m groups of regulating resistors according to the wiring resistance values ​​of each branch so as to make the total impedance of all branches equal.

[0053] In order to explain the electronic paper driving module of this embodiment in detail, this embodiment further provides an electronic paper that realizes a display function by utilizing different states of cholesteric liquid crystal.

[0054] It should be noted that cholesteric liquid crystal (CLC) can present multiple states under different conditions, the most common of which include H state, P state and FC state. The following is a detailed description of these states:

[0055] 1. H state (Homeotropic State)

[0056] Features: The liquid crystal molecules are arranged perpendicular to the substrate surface, the spiral structure is destroyed, and the spiral axis of the cholesteric phase disappears.

[0057] Formation conditions: Usually formed under the action of strong electric field or surface treatment (such as vertical alignment layer).

[0058] Optical properties: It appears transparent because the molecules are arranged evenly and light passes through without scattering or selective reflection.

[0059] Applications: Used in electrically controlled optical devices, such as fast-switching transparent / scattering state displays.

[0060] 2. P state (Planar State)

[0061] Features: Liquid crystal molecules are arranged in a plane parallel to the substrate, the spiral axis is perpendicular to the substrate surface, and the spiral structure is complete.

[0062] Formation conditions: The state in which cholesteric liquid crystal naturally appears in the absence of an external electric field or in a weak electric field.

[0063] Optical properties: Exhibits selective reflection, with the wavelength of reflected light determined by the pitch, usually appearing in bright colors.

[0064] Applications: Used in reflective displays, optical filters and color display devices.

[0065] The electronic paper of this embodiment utilizes an active cholesteric LCD single-pixel drive architecture, primarily consisting of a gate line on the thin-film transistor substrate side, a source line, a thin-film transistor, a common line on the color filter substrate side, and a pixel unit. The pixel unit's state is controlled by applying a voltage between the common electrode of the color filter substrate and the pixel electrode of the thin-film transistor substrate. The source line transmits data to the drain of the thin-film transistor, while the gate line controls the gate of the thin-film transistor to turn it on or off. The pixel unit, connected to the source of the thin-film transistor, receives and stores data signals, forming an electric field with the common electrode to control the deflection of the liquid crystal.

[0066] The existing active drive solution applies a periodic voltage (+common voltage → 0 → -common voltage → 0V) to the liquid crystal units of the liquid crystal layer through the AC common-level traces on the color filter substrate side. However, in large-size modules, the gradient distribution of the AC common-level trace resistance, that is, low resistance on both sides and high resistance in the middle, leads to serious uneven charging and discharging currents. When the current in the branches on both sides is too high, it can easily cause the binding pins to burn out. When the current in the middle branch is too low, it affects the response speed of the liquid crystal. The high current area accelerates aging at high temperatures, causing the screen to fail.

[0067] Therefore, this embodiment compensates for the uneven current distribution caused by the difference in wiring resistance by connecting differentiated adjustment resistors in series in different branches, making the total impedance of all branches equal, thereby balancing the charge and discharge current and avoiding the problem of device burning caused by local overcurrent in a high-temperature environment.

[0068] In a specific implementation of this embodiment, the impedance balancing logic unit includes:

[0069] A data acquisition module is used to obtain the wiring resistance value of each of the n branches through simulation modeling or actual measurement;

[0070] The compensation calculation module calculates the corresponding compensation resistance value according to the wiring resistance value, that is, the resistance value of the adjustment resistor.

[0071] In this embodiment, a set of regulating resistors is connected in series between any two branches of the n branches, specifically:

[0072] The n branches are arranged from top to bottom based on the position of the main drive port. Each branch corresponds to a group of regulating resistors connected in series, where:

[0073] The first branch and the nth branch are connected in series with a first regulating resistor R1;

[0074] The second branch and the (n-1)th branch are connected in series with a second regulating resistor R2;

[0075] The third branch and the (n-2)th branch are connected in series with a third regulating resistor R3;

[0076] Similarly, the kth branch and the (n-k+1)th branch are connected in series with the kth regulating resistor Rk, where k=1, 2,…, m.

[0077] In this embodiment, the resistance values ​​corresponding to the m groups of regulating resistors decrease from both sides to the middle according to the corresponding branch positions.

[0078] Specifically, the adjustment resistor unit includes m types of adjustment resistors with different resistance values ​​(R1, R2, ..., Rm, and satisfying R1>R2>...>Rm), and the resistance values ​​are distributed according to the symmetrical positions of the branches, specifically: the two branches farthest from the total drive port are connected in series with R1 with the largest resistance; if the number of branches n≥4, the two branches next farthest away are connected in series with R2 with the second largest resistance; and so on, the middle branch (exists when n≥2m+1) is connected in series with Rm with the smallest resistance; through the resistance gradient configuration, the total impedance of all branches is equal.

[0079] In a specific embodiment, Figure 7-Figure 9As shown, when the n branches are specifically six branches, the first branch and the sixth branch are connected in series with the first regulating resistor R1, the second branch and the fifth branch are connected in series with the second regulating resistor R2; the third branch and the fourth branch are connected in series with the third regulating resistor R3, wherein the resistance relationship among the first regulating resistor R1, the second regulating resistor R2 and the third regulating resistor R3 satisfies R1>R2>R3.

[0080] Specifically, resistors are connected in series at the locations where the six branches P1 through P6 connect to the main AC common-level port, aligning the impedance of the 12 parallel signal lines corresponding to the six branches. P1 / P6 are connected in series with a high-resistance resistor R1, P2 / 5 are connected in series with a medium-resistance resistor R2, and P3 / 4 are connected in series with a low-resistance resistor R3. This adjustment limits the current in each branch to less than 2.6A while ensuring a consistent total discharge current. The addition of resistors reduces the current somewhat, but does not affect normal charging and discharging speeds. Since the current output of all branches is essentially the same after this adjustment, the ports are less likely to burn out.

[0081] Will Figure 7 The drive structure shown is equivalent to Figure 8 In the model shown, the AC common-state charges and discharges the six branches P1 to P6 from the left and right sides. Since the distance between the charging and discharging paths of the six branches P1 to P6 is close, the 0.5Ω resistance in the middle can be ignored. The two paths in each branch are equivalent to parallel resistances. The equivalent parallel resistance of the six branches P1 to P6 is 2.8Ω per group. The intermediate series resistance is as follows: Figure 8 The values ​​shown are: 2.3Ω, 32.2Ω, 100Ω, 32.1Ω, and 2.4Ω respectively. Based on the AC common voltage of 30V, the initial currents flowing through P1 to P6 are calculated to be 10.89A, 6.06A, 1.02A, 1.01A, 5.95A, and 10.89A respectively.

[0082] For the six branches P1~P6, resistors are connected in series. In this embodiment, since branches P3~4 are already below 2.6A, no additional resistors are needed. The corresponding resistances of the six branches P1~P6 are: 6Ω, 4Ω, 2.8Ω, 2.8Ω, 4Ω, 6Ω. After calculation, the corresponding single-channel currents of the six branches P1~P6 become: 5.18A, 4.94A, 1.02A, 0.95A, 4.86A, 5.17A. Each of the six branches P1~P6 has two discharge paths, so the single-channel discharge paths of the six branches P1~P6 become: 2.59A, 2.47A, 0.51A, 0.48A, 2.43A, 2.59A; the final output is as follows Figure 9 shown.

[0083] Specifically, such as Figure 8 As shown, the resistance configuration of each group of regulating resistors in the regulating resistor unit satisfies: ;

[0084] in, is the total resistance value of any branch among the n branches; is the wiring resistance value of any branch among the n branches; is the resistance of the regulating resistor corresponding to any one of the n branches.

[0085] In this embodiment, it also includes:

[0086] The dynamic feedback module is used to monitor the current value of each branch in real time and adjust the resistance value according to the current deviation to stabilize the current within the preset range.

[0087] The electronic paper proposed in the present invention includes any one of the electronic paper driving modules described above.

[0088] This embodiment is particularly suitable for large-sized cholesteric liquid crystal electronic paper modules, and significantly improves the reliability and service life of the product.

[0089] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. An electronic paper driving module, characterized in that: include: The main driving port is used to output a periodic voltage sequence; A parallel branch group includes n branches, one end of each branch is connected to the main driving port, and the other end is connected to the cholesteric liquid crystal layer of the electronic paper module through an AC common-level terminal wiring; The regulating resistor unit includes m groups of regulating resistors, and a group of regulating resistors is connected in series between any two branches in the n branches, where n ≥ 4 and m ≥ 2; an impedance balancing logic unit, configured to configure the resistance values ​​of the m groups of adjusting resistors according to the wiring resistance values ​​of each branch so as to make the total impedance of all branches equal; The n branches are arranged from top to bottom based on the position of the main drive port. Each branch corresponds to a group of regulating resistors connected in series, where: The first branch and the nth branch are connected in series with a first regulating resistor R1; The second branch and the (n-1)th branch are connected in series with a second regulating resistor R2; The third branch and the (n-2)th branch are connected in series with a third regulating resistor R3; Similarly, the kth branch and the n-k+1th branch are connected in series with the kth regulating resistor Rk, where k=1, 2,…, m; The resistance values ​​corresponding to the m groups of regulating resistors decrease from both sides to the middle according to the corresponding branch positions.

2. The electronic paper driving module according to claim 1, characterized in that: When the n branches are specifically six branches, the first branch and the sixth branch are connected in series with the first regulating resistor R1, the second branch and the fifth branch are connected in series with the second regulating resistor R2; the third branch and the fourth branch are connected in series with the third regulating resistor R3, wherein the resistance relationship of the first regulating resistor R1, the second regulating resistor R2 and the third regulating resistor R3 satisfies R1>R2>R3.

3. The electronic paper driving module according to claim 1, wherein: The resistance configuration of each group of regulating resistors in the regulating resistor unit satisfies: ; in, is the total resistance value of any branch among the n branches; is the wiring resistance value of any branch among the n branches; is the resistance of the regulating resistor corresponding to any one of the n branches.

4. The electronic paper driving module according to claim 3, characterized in that: The impedance balancing logic unit includes: A data acquisition module is used to obtain the wiring resistance value of each of the n branches through simulation modeling or actual measurement; The compensation calculation module calculates the corresponding compensation resistance value, that is, the resistance value of the adjustment resistor, according to the wiring resistance value.

5. The electronic paper driving module according to claim 1, wherein: The application timing of the periodic voltage sequence is: The first stage t1: applying a positive common voltage for a duration of t1 to drive the liquid crystal molecules to switch to the H state; The second stage t2: drops to 0V, lasts for t2, and stabilizes the electric field distribution; The third stage t3: applying a negative common voltage for a duration of t3 to drive the liquid crystal molecules to switch to the P state or FC state; The fourth stage t4: drops to 0V again, lasting for t4, completing the charge and discharge cycle.

6. The electronic paper driving module according to claim 1, characterized in that: Also includes: The dynamic feedback module is used to monitor the current value of each branch in real time and adjust the resistance value according to the current deviation to stabilize the current within the preset range.

7. An electronic paper, characterized in that: The electronic paper driving module comprises the electronic paper driving module according to any one of claims 1 to 6.

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