Waveform design method for four-color electronic paper aiming at low-temperature yellowish red problem

Abstract

The invention relates to the technical field of electronic paper displays, in particular to a waveform design method for four-color electronic paper for solving the problem that low-temperature red is yellowish. The specific design method comprises the following steps: step 1, determining a voltage stable value VR * of a red particle of the electronic paper diaphragm; step 2, adding a red particle pre-pushing area in the low-temperature refresh waveform; 3, determining the springback waiting step length of the red particles in the display area; and 4, adding a color complementing area at the rear end of the display area. According to the invention, by determining the voltage stable value VR * of the red particle, the red particle can have the best driving capability at a low temperature; the red particle pre-pushing area is added, it is guaranteed that the red particles cannot rebound to the position below the yellow particles due to the over-pushing problem in the display stage, and finally the color complementing area is added to the rear end of the display area, so that the problem that the red color is slightly yellow when the four-color electronic paper is placed at the low temperature for a long time is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic paper displays, and in particular to a waveform design method for four-color electronic paper to solve the problem of red color being yellowish at low temperatures. Background Art

[0002] The display industry has highly responded to the country's low-carbon development concept and launched electronic paper displays. Electronic paper displays have a paper-like display effect, can protect the eyes, have long-term display capabilities, and have zero power consumption characteristics.

[0003] Electronic paper displays can be divided into two-color, three-color, four-color, seven-color and full-color electronic paper displays according to color. Among them, black-white-red-yellow electronic paper displays are currently widely used in retail, education, medical and other industries. For example, they are commonly used in supermarket price tags, conference table signs and door signs. The electronic paper membrane used in the black-white-red-yellow electronic paper display is filled with charged particles of four colors: black, white, red and yellow. The display of the electronic paper display is realized by changing the polarity of the electric field. Since the charged particles of the four colors have different charges, it is very difficult to control the display. In particular, some electronic paper modules will appear reddish and yellowish when placed in low temperature conditions for a long time.

[0004] The low temperature refresh waveform of conventional four-color electronic paper includes a balancing area, a vibration area, and a display area, such as Figure 1 As shown. The vibration area can vibrate the four particles of black, white, red and yellow to the middle of the electronic paper membrane, so that the four particles are kept on the same horizontal line, which is convenient for the display area to drive the particles of various colors to the position with the best display effect. Because the four particles are gathered together after the vibration area, the red particles and the yellow particles also have overlapping parts. When the display area drives the red particles to move to the top of the electronic paper membrane, the yellow particles overlapping the red particles will also move upward with the red particles, resulting in the final display effect to be red and yellowish. Summary of the invention

[0005] In order to overcome the defects of the prior art, the technical problem solved by the present invention is to provide a waveform design method for four-color electronic paper to solve the problem of red yellowing at low temperature. The present invention can solve the problem of red yellowing when four-color electronic paper is placed at low temperature for a long time.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A waveform design method for four-color electronic paper to solve the problem of red yellowing at low temperature, the specific design method is as follows:

[0008] Step 1: Determine the voltage stability value VR* of the red particles of the electronic paper film;

[0009] Step 2: Add a red particle pre-push area to the low temperature refresh waveform;

[0010] Step 3: Determine the rebound waiting step length of the red particles in the display area;

[0011] Step 4: Add a complementary color area at the back end of the display area.

[0012] The voltage stability value of the red particles in step 1 ranges from 3 to 14V.

[0013] Taking 3V as the starting value, 0.2V as the increasing value and 14V as the ending value, the red particles are driven to display the red color of the electronic paper module at different voltages, and the optical values ​​are measured to draw the VR curve of the red particles. After the Ra* value rises to the Max value, the regional stability state will be presented. At this time, the RL* value is also in a stable state. The voltage stability value VR* of the red particles is 0.2~1.2V higher than the voltage value corresponding to the Max point of the Ra* value.

[0014] In the step 2, a pre-push area is added between the vibration area and the display area of ​​the low-temperature refresh waveform; in the pre-push area, +15V is first used to drive the black particles to move toward the top of the electronic paper membrane, with a step range of 1 to 3. While driving the black particles to move toward the top of the electronic paper membrane, the yellow particles will move toward the bottom of the electronic paper membrane, and then VR* is used to drive the red particles to move toward the top of the electronic paper membrane. This process is repeated 20 to 25 times.

[0015] In the third step, in the display area, the red particles are processed in three stages excellently. In the first excellent stage, first use -15V to drive the yellow particles to move towards the top of the electronic paper diaphragm with a step size of N1 to enhance the red brightness. Subsequently, use VR* to drive the red particles to move towards the top of the electronic paper diaphragm with a step size of N2. This process is repeated 8 to 10 times. In the second excellent stage, first use -15V to drive the yellow particles to move towards the top of the electronic paper diaphragm with a step size of N3, where N3 < N1, to consolidate the red brightness RL*. Subsequently, use VR* to drive the red particles to move towards the top of the electronic paper diaphragm with a step size of N4, where N4 > N2. After driving the red particles, no voltage is applied to the electronic paper diaphragm and wait with a step size of N5 to make the red particles stable. This process is repeated 8 to 10 times. In the third excellent stage, which is the same as the second excellent stage, first use -15V to drive the yellow particles to move towards the top of the electronic paper diaphragm with a step size of N6, where N6 = N3, to consolidate the red brightness RL*. Subsequently, use VR* to drive the red particles to move towards the top of the electronic paper diaphragm with a step size of N7, where N7 > N4, to consolidate the display of the red particles. After driving the red particles, no voltage is applied to the electronic paper diaphragm and wait with a step size of N8, where N8 > N5, to make the red particles stable and prevent the phenomenon that the red particles bounce down after reaching the top of the electronic paper diaphragm. This process is repeated 3 to 5 times to enhance the display of the red particles.

[0016] In the third stage, determine the optimal value of the N8 step size so that the red particles can move smoothly towards the top of the electronic paper each time without bouncing down. It can be set that N8 = 1.5 * N5, N8 = 2 * N5, and so on. Then measure the red optical value. When the Ra* of the red optical value reaches Max, the corresponding N8 value is the waiting step size for the red particles to be stable.

[0017] In the fourth step, in the complementary color area, first use the VR* voltage to drive the red particles to move towards the top of the electronic paper diaphragm with a step size of N9, where N9 > N7. Subsequently, use +15V to drive the black particles to move towards the top of the electronic paper diaphragm with a step size of N10, and the range of N10 is 5 to 20. When driving the black particles towards the top of the electronic paper diaphragm, the yellow particles will move towards the bottom of the electronic paper diaphragm. Then use VR* to drive the red particles to move towards the top of the electronic paper diaphragm with a step size of N11.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] The waveform design method of the present invention solves the problem that the red color will be yellowish when the four-color electronic paper is placed under low temperature conditions for a long time. By determining the voltage stability value VR* of the red particles, the red particles can have the best driving ability at low temperatures; adding a red particle pre-push area allows the red particles to be suspended in the upper layer of the electronic paper membrane, and by determining the waiting step length for the end of the rebound of the red particles, it is ensured that the red particles will not rebound to the bottom of the yellow particles due to the problem of over-push during the display stage. Finally, by adding a complementary color area at the rear end of the display area, the black particles are driven. While driving the black particles to move to the top of the electronic paper membrane, the yellow particles will be moved to the bottom of the electronic paper membrane, solving the problem of the red color being yellowish when the four-color electronic paper is placed at low temperatures for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 This is a conventional low-temperature refresh waveform timing diagram.

[0022] Figure 2 It is the VR curve graph of red particles.

[0023] Figure 3 It is a low temperature refresh waveform timing diagram of the present invention.

[0024] Figure 4 It is the waveform structure diagram of the red particle display area.

[0025] Figure 5 It is a waveform structure diagram of the complementary color area of ​​red particles.

[0026] Figure 6 This is a low-temperature display effect diagram of the present invention. DETAILED DESCRIPTION

[0027] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0028] The present invention provides a waveform design method for four-color electronic paper to solve the problem of red color being yellowish at low temperature. The specific design method is as follows:

[0029] Step 1: Determine the voltage stability value VR* of the red particles of the electronic paper film.

[0030] The voltage stability value of the red particles ranges from 3 to 14 V. With 3 V as the starting value, 0.2 V as the increasing value, and 14 V as the ending value, the red particles are driven to display the red color of the electronic paper module at different voltages, and the optical values ​​are measured to draw the VR curve of the red particles, as shown in the figure. Figure 2As shown, after the Ra* value rises to the Max value, it will present a stable state in a region. At this time, the RL* value is also in a stable state. The stable voltage value VR* of the red particles is 0.2V higher than the voltage value corresponding to the Max point of the Ra* value. In the subsequent steps, the stable voltage value VR* needs to be used for driving the red particles. The stable voltage value determined in this way can ensure that when the electronic paper is refreshed and displayed at low temperature, the red color will not turn yellow due to the unstable voltage of the red particles.

[0031] Step 2: Add a pre-push area for red particles in the low-temperature refresh waveform.

[0032] In the second step described above, a pre-push area is added between the vibration area and the display area of the low-temperature refresh waveform, as Figure 3 shown. In the pre-push area, first use +15V to drive the black particles to move towards the top of the electronic paper diaphragm, with a step size of 1. While driving the black particles to move towards the top of the electronic paper diaphragm, the yellow particles will move towards the bottom of the electronic paper diaphragm. Then use VR* to drive the red particles to move towards the top of the electronic paper diaphragm. This process is repeated 20 times. Such an operation makes the yellow particles be placed below the red particles, ensuring that when the display area is excellent, when driving the red particles, the yellow particles will not move upward together due to the presence of yellow particles above. Therefore, the phenomenon of red turning yellow can be avoided.

[0033] Step 3: Determine the bounce waiting step size of the red particles in the display area.

[0034] In the display area, the red particles are subjected to three-stage excellence, as Figure 4 shown.

[0035] In the first stage of excellence, first use -15V to drive the yellow particles to move towards the top of the electronic paper diaphragm, with a step size of N1, to enhance the red brightness. Subsequently, use VR* to drive the red particles to move towards the top of the electronic paper diaphragm, with a step size of N2. This process is repeated 8 times. This is to ensure that the red particles will not be covered by the yellow particles and to enhance the red brightness value RL*.

[0036] In the second stage of excellence, first use -15V to drive the yellow particles to move towards the top of the electronic paper diaphragm, with a step size of N3, where N3 < N1, to consolidate the red brightness RL*. Subsequently, use VR* to drive the red particles to move towards the top of the electronic paper diaphragm, with a step size of N4, where N4 > N2. After driving the red particles, no voltage is applied to the electronic paper diaphragm, and wait for a step size of N5 to make the red particles stable. This process is repeated 8 times.

[0037] The third stage is excellent, just like the second stage. First, -15V is used to drive the yellow particles to move to the top of the electronic paper membrane with a step length of N6, where N6=N3, to consolidate the red brightness RL*, and then VR* is used to drive the red particles to move to the top of the electronic paper membrane with a step length of N7, where N7>N4, to consolidate the display of the red particles. After driving the red particles, no voltage is applied to the electronic paper membrane, and the waiting step is N8, where N8>N5, to stabilize the red particles and prevent the red particles from rebounding downward after reaching the top of the electronic paper membrane. This process is repeated 3 times to enhance the display of the red particles.

[0038] In the third stage, the optimal value of the N8 step length is determined so that the red particles can move smoothly to the top of the electronic paper every time without rebounding downward. N8=1.5*N5, N8=2*N5... and so on can be set, and the red optical value is measured. When the red optical value Ra* reaches Max, the corresponding N8 value is the stable waiting step length of the red particles.

[0039] In the third stage, the optimal value of N8 step length is determined, so that the red particles can move smoothly to the top of the electronic paper every time without rebounding downwards. By setting N8=1.5*N5, N8=2*N5... and so on, and measuring the optical value, when the Ra* of the red particle reaches the peak, the corresponding N8 value is the waiting step length for the red particle to rebound smoothly. The determination of this step length can make the red particles stable, and will not cause the red particles to rebound below the yellow particles due to excessive pushing of the red particles, so that when the red particles are pushed later, the yellow particles will not be driven upward together, causing the red to be yellowish.

[0040] Step 4: Add a complementary color area at the back end of the display area.

[0041] like Figure 5 As shown, in the complementary color area, first use VR* voltage to drive the red particles to move to the top of the electronic paper membrane, the step length is N9, N9>N7, then use +15V to drive the black particles to move to the top of the electronic paper membrane, the step length is N10, N10 is 5, while driving the black particles to move to the top of the electronic paper membrane, the yellow particles will move to the bottom of the electronic paper membrane, and the red particles will be kept suspended on the upper layer of the electronic paper. Then use VR* to drive the red particles to move to the top of the electronic paper membrane, the step length is N11, to ensure that the low temperature red will not appear yellowish.

[0042] The same electronic paper module is tested at low temperature using the conventional low-temperature refresh waveform and the low-temperature refresh waveform of the present invention at the same time. The red optical data (RL*, Ra*, Rb*) are as follows:

[0043] The data for applying the conventional low temperature refresh waveform is as follows:

[0044]

[0045] The data of the low temperature refresh waveform using the present invention are as follows:

[0046]

[0047] It can be seen that the red optical value is higher than the standard and the display state is good when the waveform of the present invention is applied. Figure 6 .

[0048] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. In addition, the various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A waveform design method for four-color electronic paper to solve the problem of red and yellow at low temperature, characterized in that: The specific design method is as follows: Step 1: Determine the voltage stability value VR* of the red particles in the e-paper film; Step 2: Add a pre-push area for the red particles in the low-temperature refresh waveform; Step 3: Determine the bounce waiting step length of the red particles in the display area; Step 4: Add a complementary color area at the back end of the display area.

2. The waveform design method for a four-color electronic paper for the problem of reddish yellowing at low temperatures according to claim 1, characterized in that: In Step 1, the voltage stability value of the red particles ranges from 3V to 14V.

3. The waveform design method for four-color electronic paper for the problem of red yellowing at low temperature according to claim 2, characterized in that: Starting from 3V, with an increment of 0.2V and an end value of 14V, at different voltages, drive the red particles to perform red display of the e-paper module and measure the optical values, and plot the VR curve of the red particles. The Ra* value will呈现 a stable state after rising to the Max value. At this time, the RL* value is also in a stable state. The voltage stability value VR* of the red particles is increased by 0.2V to 1.2V based on the voltage value corresponding to the Max point of the Ra* value.

4. The waveform design method for four-color electronic paper for the problem of red and yellowing at low temperatures according to claim 1, characterized in that: In Step 2, add a pre-push area between the vibration area and the display area of the low-temperature refresh waveform; in the pre-push area, first use +15V to drive the black particles to move towards the top of the e-paper film, with a step length range of 1 to 3. While driving the black particles to move towards the top of the e-paper film, the yellow particles will move towards the bottom of the e-paper film. Then use VR* to drive the red particles to move towards the top of the e-paper film, and this process is repeated 20 to 25 times.

5. The waveform design method for four-color electronic paper to solve the problem of red yellowing at low temperature according to claim 1, characterized in that: In Step 3, in the display area, perform three-stage enhancement on the red particles; in the first stage of enhancement, first use -15V to drive the yellow particles to move towards the top of the e-paper film, with a step length of N1, to increase the red brightness. Subsequently, use VR* to drive the red particles to move towards the top of the e-paper film, with a step length of N2, and this process is repeated 8 to 10 times; in the second stage of enhancement, first use -15V to drive the yellow particles to move towards the top of the e-paper film, with a step length of N3, where N3 < N1, to consolidate the red brightness RL*. Subsequently, use VR* to drive the red particles to move towards the top of the e-paper film, with a step length of N4, where N4 > N2. After driving the red particles, no voltage is applied to the e-paper film and wait, with a waiting step length of N5, to make the red particles stable. This process is repeated 8 to 10 times; in the third stage of enhancement, it is the same as the second stage of enhancement. First use -15V to drive the yellow particles to move towards the top of the e-paper film, with a step length of N6, where N6 = N3, to consolidate the red brightness RL*. Subsequently, use VR* to drive the red particles to move towards the top of the e-paper film, with a step length of N7, where N7 > N4, to consolidate the display of the red particles. After driving the red particles, no voltage is applied to the e-paper film and wait, with a waiting step length of N8, where N8 > N5, to make the red particles stable and prevent the phenomenon that the red particles bounce down after reaching the top of the e-paper film. This process is repeated 3 to 5 times to strengthen the display of the red particles; In the third stage, the optimal value of the N8 step length is determined so that the red particles can move smoothly to the top of the electronic paper every time without rebounding downward. N8=1.5*N5, N8=2*N5... and so on can be set, and the red optical value is measured. When the red optical value Ra* reaches Max, the corresponding N8 value is the stable waiting step length of the red particles.

6. The waveform design method for four-color electronic paper to solve the problem of red and yellow at low temperature according to claim 1, characterized in that: In the step 4, in the complementary color area, the VR* voltage is first used to drive the red particles to move toward the top of the electronic paper membrane, with a step length of N9, N9>N7, and then +15V is used to drive the black particles to move toward the top of the electronic paper membrane, with a step length of N10, and the N10 range is 5 to 20. While driving the black particles to move toward the top of the electronic paper membrane, the yellow particles will move to the bottom of the electronic paper membrane, and then VR* is used to drive the red particles to move toward the top of the electronic paper membrane, with a step length of N11.

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