Liquid crystal grating and holographic three-dimensional display device

Abstract

The application discloses a liquid crystal grating and a holographic three-dimensional display device. The liquid crystal grating comprises a plurality of first electrodes, a first driving circuit for providing a driving signal for the first electrodes, and a first driving circuit comprising a first switch unit, a second switch unit and a storage unit. A first input end of the first switch unit receives a data signal, and a second input end of the second switch unit receives a first signal. A first plate of the storage unit is electrically connected to the first electrode, and the first plate is also electrically connected to a first output end of the first switch unit. A second plate is electrically connected to a second output end of the second switch unit. In a charging stage in a driving cycle of the liquid crystal grating, the second switch unit transmits a first level signal to the second plate. In a charge pumping stage in the driving cycle of the liquid crystal grating, the second switch unit transmits a second level signal to the second plate. The first level signal and the second level signal have different potentials. The application can simplify the circuit structure.

Description

Technical Field

[0001] This application belongs to the field of display technology, and in particular relates to a liquid crystal grating and a holographic three-dimensional display device. Background Technology

[0002] Holographic 3D display technology is the only truly three-dimensional display technology among various display methods. Liquid crystal grating (LCG), as part of the eye-tracking system in holographic 3D displays, can control the movement of the viewing window.

[0003] However, due to the high refresh rate required by the electrodes in the liquid crystal grating and the large resistance and capacitance of the electrodes, the grating is often not fully charged within a limited time. To improve this phenomenon and increase charging efficiency, a charge pump circuit is added to the grating driving circuit in related technologies. However, the current charge pump circuit has a complex circuit structure, resulting in a large bezel area in the final panel. Summary of the Invention

[0004] This application provides a liquid crystal grating and a holographic three-dimensional display device, which can simplify the circuit structure, indirectly reduce the panel bezel ratio, and improve charging performance.

[0005] On the one hand, a liquid crystal grating is provided, including a first driving circuit and a plurality of first electrodes, wherein the first driving circuit is capable of providing driving signals to the first electrodes.

[0006] The first driving circuit includes a first switching unit, a second switching unit, and a storage unit.

[0007] The first input terminal of the first switching unit receives a data signal, and the second input terminal of the second switching unit receives a first signal.

[0008] The storage unit includes a first electrode plate and a second electrode plate. The first electrode plate is electrically connected to a first electrode and is also electrically connected to a first output terminal of a first switching unit; the second electrode plate is electrically connected to a second output terminal of a second switching unit.

[0009] One driving cycle of a liquid crystal grating includes a charging phase and a charge pumping phase;

[0010] During the charging phase, the second switching unit transmits a first-level signal to the second electrode plate;

[0011] During the charge pumping phase, the second switching unit transmits a second-level signal to the second electrode plate; the potentials of the first-level signal and the second-level signal are different.

[0012] On the other hand, a holographic three-dimensional display device is provided, the holographic three-dimensional display device including a liquid crystal grating, the liquid crystal grating being configured as described above.

[0013] Compared with the prior art, the liquid crystal grating and holographic three-dimensional display device provided in this application embodiment are provided with a first driving circuit and multiple first electrodes. The first driving circuit can provide driving signals to the first electrodes. The first driving circuit includes a first switching unit, a second switching unit, and a storage unit. The first input terminal of the first switching unit receives a data signal, and the second input terminal of the second switching unit receives a first signal. The storage unit includes a first electrode plate and a second electrode plate. The first electrode plate is electrically connected to the first electrode and is also electrically connected to the first output terminal of the first switching unit. The second electrode plate is electrically connected to the second output terminal of the second switching unit. A driving cycle of the liquid crystal grating includes a charging phase and a charge pumping phase. In the charging phase, the second switching unit transmits a first level signal to the second electrode plate. In the charge pumping phase, the second switching unit transmits a second level signal to the second electrode plate. The potentials of the first level signal and the second level signal are different. Therefore, by reusing the first signal and changing the output potential of the first signal during the charge pumping stage, the reset of the second plate is achieved. Compared with related technologies, this simplifies the structure and layout of the driving circuit, indirectly increases the storage capacity of the storage unit, helps improve charging performance, and the simplification of the circuit structure also helps reduce the proportion of the panel bezel. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a circuit structure diagram of a liquid crystal grating according to an embodiment of this application, which relates to related technologies.

[0016] Figure 2 This is an optional circuit structure diagram of a liquid crystal grating according to an embodiment of this application.

[0017] Figure 3 This is an optional circuit structure diagram of a liquid crystal grating according to an embodiment of this application.

[0018] Figure 4 This is an optional signal timing diagram related to a liquid crystal grating in an embodiment of this application.

[0019] Figure 5 This is an optional circuit structure diagram of the first driving circuit in a liquid crystal grating according to an embodiment of this application.

[0020] Figure 6 This is an optional circuit structure diagram of a liquid crystal grating according to an embodiment of this application.

[0021] Figure 7 This is an optional circuit structure diagram of the first driving circuit and the reset unit in a liquid crystal grating according to an embodiment of this application.

[0022] Figure 8 This is an optional circuit structure diagram of a liquid crystal grating according to an embodiment of this application.

[0023] Figure 9 This is a schematic diagram of the planar structure of the first electrode, the second electrode, and the liquid crystal layer in a liquid crystal grating according to an embodiment of this application.

[0024] Figure 10 This is an optional circuit structure diagram of a liquid crystal grating according to an embodiment of this application.

[0025] Figure 11 This is an optional circuit structure diagram of the second driving circuit in a liquid crystal grating according to an embodiment of this application.

[0026] Figure 12 This is a schematic diagram of the circuit layout of the first driving circuit and the second driving circuit in a liquid crystal grating according to an embodiment of this application. Detailed Implementation

[0027] The features and exemplary embodiments of various aspects of this application will now be described in detail. Numerous specific details are set forth in the following detailed description in order to provide a comprehensive understanding of this application. However, it will be apparent to those skilled in the art that this application can be implemented without some of these specific details. The following description of embodiments is merely intended to provide a better understanding of this application by illustrating examples thereof.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The embodiments will now be described in detail with reference to the accompanying drawings.

[0029] Holographic 3D display technology is the only technology among various display methods that truly achieves three-dimensional display. It utilizes light diffraction or interference to record the amplitude and phase information of the object light, and then reconstructs this information through light diffraction.

[0030] When performing holographic 3D displays, the holographic 3D display device needs to be equipped with structures such as a spatial light modulator, polarizer, volume holographic grating, and liquid crystal grating. Among them, the liquid crystal grating is an important component of the eye-tracking system in holographic 3D displays, which can control the movement of the viewing window.

[0031] To accommodate the movement of the human eye, liquid crystal gratings require a high refresh rate; for example, the refresh rate is typically greater than 120 Hz. However, due to the large resistance and capacitance of the electrodes in the liquid crystal grating (e.g., greater than 10 picofarads), the grating is often not fully charged. Since the charging performance of the driving chip in the liquid crystal grating has an upper limit, to improve this phenomenon and increase the grating charging efficiency, related technologies incorporate a charge pump circuit into the grating driving circuit.

[0032] See Figure 1 , Figure 1 This is a schematic diagram of the charge pump circuit involved in related technologies. The circuit structure of this charge pump circuit is relatively complex, increasing the panel bezel ratio of the holographic 3D display device. If the panel bezel ratio needs to remain unchanged, then this charge pump circuit relatively reduces the size of the storage unit. This storage unit plays a crucial role in raising the potential in the charge pump circuit; therefore, the charge pump circuit in related technologies also affects the charging performance of the liquid crystal grating.

[0033] To improve at least one of the above-mentioned technical problems, this application provides a liquid crystal grating and a holographic three-dimensional display device. The liquid crystal grating of this application embodiment will be described below with reference to the accompanying drawings.

[0034] See Figure 2 ,in Figure 2 A schematic diagram of the module structure of an optional example of a liquid crystal grating in this application is shown. In this example, the liquid crystal grating includes a first driving circuit 20 and a plurality of first electrodes 10. The first driving circuit 20 is capable of providing driving signals to the first electrodes 10, which can control the deflection of liquid crystal according to the driving signals.

[0035] For example, the first driving circuit 20 described above can be connected one-to-one with the first electrode 10.

[0036] For example, a portion of the first electrode 10 in the liquid crystal grating can be connected to the first driving circuit 20, while another portion of the first electrode 10 can be electrically connected to other driving circuits.

[0037] The first driving circuit 20 mentioned above may include a first switching unit 21, a second switching unit 22, and a storage unit Cst.

[0038] The first switching unit 21 may include a first input terminal A1 and a first output terminal A2, and the second switching unit 22 may include a second input terminal B1 and a second output terminal B2. The first input terminal A1 of the first switching unit 21 may receive a data signal, and the second input terminal B1 of the second switching unit 22 may receive a first signal.

[0039] The storage unit Cst can be a capacitor or other type, and the storage unit Cst can include a first electrode J1 and a second electrode J2. The first electrode J1 can be electrically connected to the first electrode 10, and the first electrode J1 is also electrically connected to the first output terminal A2 of the first switching unit 21. The second electrode J2 can be electrically connected to the second output terminal B2 of the second switching unit 22.

[0040] The first switching unit 21 described above can control the first plate J1 of the storage unit Cst to selectively receive data signals, which can be provided by the data signal line Source.

[0041] The second switching unit 22 described above can control the second plate J2 of the storage unit Cst to selectively receive the first signal, which can be provided by the first signal line S.

[0042] It should be noted that the first switching unit 21, the second switching unit 22 and the storage unit Cst constitute a charge pump circuit, which can convert the data signal received by the first input terminal A1 of the first switching unit 21 into a voltage, thereby improving the driving signal and the potential of the first electrode 10 in the liquid crystal grating, and thus improving the charging performance of the liquid crystal grating.

[0043] A driving cycle of the liquid crystal grating includes a charging phase and a charge pumping phase. When the potential of a single first electrode 10 is increased, the charging phase and the charge pumping phase can be set sequentially.

[0044] During the charging phase, the second switching unit 22 in the first driving circuit 20 transmits a first level signal to the second electrode J2.

[0045] The aforementioned first level signal is the first signal provided by the first signal line S during the charging phase of the driving cycle. This first level signal provides a charging signal to the second plate J2 of the storage unit Cst via the second switching unit 22, enabling the storage unit Cst to charge.

[0046] During the charge pumping phase, the second switching unit 22 in the first driving circuit 20 transmits a second-level signal to the second electrode J2. The potentials of the first-level signal and the second-level signal are different.

[0047] The aforementioned second-level signal is the first signal provided by the first signal line S during the charge pumping phase of the driving cycle. This second-level signal is transmitted to the second plate J2 of the storage unit Cst via the second switching unit 22 and is used as a reset signal. It can reset the second plate J2 of the storage unit Cst, so that the storage unit Cst can use the characteristic that the voltage between its two plates cannot change instantaneously to "pump" the raised charging voltage to the first electrode 10.

[0048] Compared to related technologies, these embodiments reuse the first signal and change the output potential of the first signal during the charge pumping phase. During the charging phase of the driving cycle, the second switching unit transmits the first level signal to the second electrode plate, and during the charge pumping phase, the second switching unit transmits the second level signal to the second electrode plate. Since the potentials of the first level signal and the second level signal are different, the reset unit originally used for resetting the second electrode plate can be omitted. While providing the same driving capability, the structure and layout of the first driving circuit are simplified, which helps to reduce the panel bezel ratio and indirectly increases the storage capacity of the storage unit, thereby improving the charging performance of the liquid crystal grating.

[0049] Please refer to Figure 2 Please continue reading for more details. Figure 3 The first switch unit 21 may further include a first control terminal A3, and the second switch unit 22 may further include a second control terminal B3.

[0050] In the first switching unit 21, the first input terminal A1 is electrically connected to the data signal line Source, the first output terminal A2 is electrically connected to the first electrode 10 and the first electrode plate J1 respectively, and the first control terminal A3 is electrically connected to the first control signal line CKH.

[0051] The aforementioned first control signal line CKH can control the opening or closing of the first switching unit 21. When the first control signal line CKH controls the first switching unit 21 to open, the data signal output by the data signal line Source can be transmitted through the first switching unit 21 to the first electrode 10 and the first plate J1 of the storage unit Cst.

[0052] In the second switching unit 22, the second input terminal B1 is electrically connected to the first signal line S, the second output terminal B2 is electrically connected to the second electrode J2, and the second control terminal B3 is electrically connected to the second control signal line SW.

[0053] The aforementioned second control signal line SW can control the second switching unit 22 to turn on or off. When the second control signal line SW controls the second switching unit 22 to turn on, the first signal output by the first signal line S can be transmitted to the second plate J2 of the storage unit Cst via the second switching unit 22.

[0054] In these examples, by setting a first control terminal A3 in the first switching unit 21 and a second control terminal B3 in the second switching unit 22, and connecting the first control terminal A3 and the second control terminal B3 to the first control signal line CKH and the second control signal line SW respectively, the storage unit Cst of the first driving circuit 20 can accurately receive the data signal and the first level signal during the charging phase, and accurately receive the second level signal during the charge pumping phase T2, thereby increasing the potential of the first electrode 10 and ensuring the charging performance of the liquid crystal grating.

[0055] In some additional optional examples, please see Figure 4 Please refer to the following as well. Figure 2 and Figure 3 During the charge pumping phase T2 of the liquid crystal grating driving cycle, the first control terminal A3 responds to the non-enable signal output by the first control signal line CKH and turns off the first switching unit 21.

[0056] The above-mentioned non-enabling signal is a signal that controls the corresponding switching unit to be turned off. In this example, the non-enabling signal is provided by the first control signal line CKH to the first control terminal A3 of the first switching unit 21, which enables the first switching unit 21 to be turned off during the charge pumping stage T2.

[0057] The potential of the disable signal is set according to the type of transistor in the first switching unit 21. For example, if the first switching unit 21 includes a P-type thin-film transistor, the disable signal can be a high-level signal. If the first switching unit 21 includes an N-type thin-film transistor, the disable signal can be a low-level signal.

[0058] During the charge pumping phase T2 of the liquid crystal grating driving cycle, the second control terminal B3 responds to the enable signal output by the second control signal line SW and turns on the second switching unit 22.

[0059] The above enable signal is the signal that controls the corresponding switch unit to be turned on. In this example, the enable signal is provided by the second control signal line SW to the second control terminal B3 of the second switch unit 22, which enables the second switch unit 22 to be turned on during the charge pumping stage T2.

[0060] The voltage of the enable signal can also be set according to the type of transistor in the second switching unit 22. For example, if the second switching unit 22 includes a P-type thin-film transistor, the enable signal can be a low-level signal. If the second switching unit 22 includes an N-type thin-film transistor, the enable signal can be a high-level signal.

[0061] In this example, during the charge pumping phase T2 of the drive cycle, the first control signal line CKH outputs a de-enabled signal to the first control terminal A3, and the first switching unit 21 is turned off. The second control signal line SW outputs an enabled signal to the second control terminal B3, and the second switching unit 22 is turned on. The second input terminal B1 is connected to a first signal at a second level, which can be transmitted to the second electrode J2 of the storage unit Cst via the second output terminal B2 of the second switching unit 22. The second electrode J2 of the storage unit Cst receives the second level signal for reset, enabling the storage unit Cst to provide a boosted voltage to the first electrode 10, achieving a rapid increase in the potential of the first electrode 10 and ensuring the charging performance of the liquid crystal grating.

[0062] Please continue reading. Figure 3 and Figure 4 In some optional examples, during the charging phase T1 of a liquid crystal grating driving cycle, the first control terminal A3 turns on the first switching unit 21 in response to the enable signal output by the first control signal line CKH, and the second control terminal B3 turns on the second switching unit 22 in response to the enable signal output by the second control signal line SW.

[0063] In this example, an enable signal can be provided by the first control signal line CKH to the first control terminal A3 of the first switching unit 21, so that the first switching unit 21 is turned on during the charging stage T1. The data signal can be transmitted as a charging signal through the first switching unit 21 to the first electrode 10 and the first plate J1 of the storage unit Cst.

[0064] An enable signal can be provided by the second control signal line SW to the second control terminal B3 of the second switch unit 22, which enables the second switch unit 22 to be turned on during the charging phase T1. The first level signal can be transmitted as the first signal through the second switch unit 22 to the second plate J2 of the storage unit Cst.

[0065] The first plate J1 and the second plate J2 of the storage unit Cst receive the data signal and the first level signal respectively, and the storage unit Cst can be charged.

[0066] In this example, the potential of the enable signal can be set according to the type of switching device in the first switching unit 21 and the second switching unit 22. For example, if the first switching unit 21 and the second switching unit 22 include a P-type thin-film transistor, the enable signal can be a low-level signal.

[0067] In this example, during the charging phase T1 of the drive cycle, the first control signal line CKH outputs an enable signal to the first control terminal A3, turning on the first switching unit 21. The data signal received at the first input terminal A1 can be output to the first electrode 10 and the first plate J1 of the storage unit Cst via the first output terminal A2 of the first switching unit 21. The second control signal line SW outputs an enable signal to the second control terminal B3, turning on the second switching unit 22. The first level signal input at the second input terminal B1 can be output to the second plate J2 of the storage unit Cst via the second output terminal B2 of the second switching unit 22. The first plate J1 and the second plate J2 of the storage unit Cst respectively receive the data signal and the first level signal for charging, enabling the storage unit Cst to charge. In the subsequent charge pumping phase T2, combined with the potential change of the first signal line S shown in the previous example, a second level signal is provided to the second plate J2 of the storage unit Cst. This second level signal has the opposite potential to the first level signal, thereby enabling the storage unit Cst to pump the potential to the first plate J1 after raising it. Thus, the entire processing of the charge pump circuit is completed with the help of the simplified first driving circuit 20 structure, ensuring the charging performance of the liquid crystal grating.

[0068] Please refer to Figure 5 Please refer to the following as well. Figure 3 and Figure 4 The first switching unit 21 may include a first transistor T1, and the second switching unit 22 may include a second transistor T2.

[0069] The input terminal of the first transistor T1 is the first input terminal A1, the output terminal of the first transistor T1 is the first output terminal A2, and the control terminal of the first transistor T1 is the first control terminal A3.

[0070] That is, the input terminal of the first transistor T1 is electrically connected to the data signal line Source, and can receive data signals. The output terminal of the first transistor T1 can be electrically connected to the first electrode 10 and the first plate J1 of the storage unit Cst. The control terminal of the first transistor T1 is electrically connected to the first control signal line CKH.

[0071] The input terminal of the second transistor T2 is the second input terminal B1, the output terminal of the second transistor T2 is the second output terminal B2, and the control terminal of the second transistor T2 is the second control terminal B3.

[0072] That is, the input terminal of the second transistor T2 receives the first signal, the output terminal of the second transistor T2 is connected to the second plate J2 of the storage cell Cst, and the control terminal of the second transistor T2 is electrically connected to the second control signal line SW.

[0073] For example, the input terminal of the transistor mentioned above can be the source of the transistor, the control terminal of the transistor can be the gate of the transistor, and the output terminal of the transistor can be the drain of the transistor.

[0074] For example, the input terminal of the transistor mentioned above can be the drain of the transistor, the control terminal of the transistor can be the gate of the transistor, and the output terminal of the transistor can be the source of the transistor.

[0075] It should also be noted that the first transistor T1 and the second transistor T2 can be of the same type, or the first transistor T1 and the second transistor T2 can be of different types.

[0076] For example, the first transistor T1 can be a P-type thin-film transistor, and the second transistor T2 can be an N-type thin-film transistor.

[0077] For example, the first transistor T1 can be an N-type thin-film transistor, and the second transistor T2 can be a P-type thin-film transistor.

[0078] Furthermore, the aspect ratio of the first transistor T1 can be greater than that of the second transistor T2, thereby improving the ability of the first switching unit 21 to receive data signals and thus enhancing the charging performance of the liquid crystal grating.

[0079] For example, the active layer of the first transistor T1 can be made of low-temperature polysilicon (LTPS) material, meaning the first transistor T1 can be a polysilicon thin-film transistor. The second transistor T2 can be an oxide thin-film transistor, such as an indium gallium zinc oxide (IGZO) thin-film transistor.

[0080] In these examples, the first switching unit 21 and the second switching unit 22 are configured differently in the first driving circuit 20 of the liquid crystal grating, which is beneficial for writing data signals and indirectly improves the charging performance of the liquid crystal grating.

[0081] In some additional optional examples, please see Figures 6 to 8 Please refer to the following as well. Figure 4 The aforementioned liquid crystal grating may include a reset module 23. The reset module 23 may provide a reset signal Vrst to the first electrode 10.

[0082] The reset module 23 may include a third input terminal C1, a third output terminal C2, and a third control terminal C3. The third input terminal C1 of the reset module 23 can be electrically connected to the reset signal line and can receive the reset signal Vrst. The third output terminal C2 is electrically connected to the first electrode 10, and the third control terminal C3 can be electrically connected to the third control signal line Rst.

[0083] The aforementioned third control signal line Rst can output different signals to the third control terminal C3, thereby controlling the on or off state of the reset module 23. When the third control signal line Rst controls the reset module 23 to be on, the reset signal Vrst output by the reset signal line can be transmitted to the first electrode 10 via the reset module 23, thereby controlling the liquid crystal grating to achieve reset. In these examples, by setting the reset module 23, the accuracy of the liquid crystal grating controlling the window movement can be indirectly guaranteed.

[0084] It should also be noted that the above-mentioned reset module 23 may include a third transistor T3, the input terminal of the third transistor T3 may be the third input terminal C1, the output terminal of the third transistor T3 may be the third output terminal C2, and the control terminal of the third transistor T3 may be the third control terminal C3.

[0085] That is, the input terminal of the third transistor T3 can be electrically connected to the reset signal line, the output terminal of the third transistor T3 can be electrically connected to the first electrode 10, and the control terminal of the third transistor T3 can be electrically connected to the third control signal line Rst.

[0086] Please continue reading. Figure 4 The aforementioned driving cycle of the liquid crystal grating includes a first driving sub-cycle T3 and a second driving sub-cycle T4. Both the first driving sub-cycle T3 and the second driving sub-cycle T4 include a data writing stage T5, a liquid crystal running stage T6, and a liquid crystal reset stage T7.

[0087] It should be noted that the first driving sub-cycle T3 can be the operating cycle when the liquid crystal raster moves the first frame window, and the second driving sub-cycle T4 can be the operating cycle when the liquid crystal raster moves the second frame window. The data writing stage T5, the liquid crystal operation stage T6, and the liquid crystal reset stage T7 within a single driving sub-cycle can be set sequentially.

[0088] The aforementioned data writing stage T5 is a driving circuit, for example, the first driving circuit 20 provides a period of driving signals to multiple first electrodes 10 in the liquid crystal grating. After the data writing is completed, the liquid crystal grating enters the liquid crystal operation stage T6. The liquid crystal grating can achieve liquid crystal deflection according to the driving signals connected to the multiple first electrodes 10, thereby completing the window movement.

[0089] Between the two window movements, that is, between the two liquid crystal operation stages T6, there is a liquid crystal reset stage T7, which is used to restore the originally deflected liquid crystal to its initial position.

[0090] It should be noted that the liquid crystal raster has high requirements for refresh rate, but due to the insufficient charging performance of the driver chip, T5 is set with multiple data writing cycles in order to meet the charging requirements of the liquid crystal raster.

[0091] For each first electrode 10 in the liquid crystal grating, there can be multiple corresponding data writing cycles. During data writing in each data writing cycle, there are charging phase T1 and charge pumping phase T2. Therefore, by setting as many data writing phases T5 as possible, the charging time of multiple first electrodes 10 can be extended. Combined with the voltage provided by the first driving circuit 20 during the data writing phase T5, which is higher than the data signal, the potential of multiple first electrodes 10 can be guaranteed, thus stabilizing the performance of the liquid crystal grating.

[0092] Please continue reading. Figure 4 as well as Figure 7 In another alternative example, during the LCD reset phase T7, the third control terminal C3 turns on the reset module 23 in response to the enable signal transmitted by the third control signal line Rst.

[0093] In this example, the enable signal transmitted by the third control signal line Rst is a signal that can control the reset module 23 to be turned on. During the liquid crystal reset stage T7 of the first driving cycle of the liquid crystal grating, the third control signal line Rst can transmit an enable signal to the third control terminal C3, turning on the reset module 23. The reset signal Vrst provided by the reset signal line can be transmitted to the first electrode 10 through the third input terminal C1 and the third output terminal C2, so that the first electrode 10 can control the liquid crystal in the liquid crystal grating to be reset according to the reset signal Vrst, thereby reducing the interference of the previous driving sub-cycle on the liquid crystal deflection in the next driving cycle and improving the operating accuracy of the liquid crystal grating.

[0094] Please refer to Figure 3 , Figure 4 , Figure 6 as well as Figure 8 In another alternative example, the plurality of first electrodes 10 respectively form different electrode groups 100, and at least some of the first electrodes 10 in an electrode group 100 have different potentials.

[0095] The division criteria of the different electrode groups 100 can be set according to actual needs. For example, the first control terminal A3 of the first drive circuit 20 corresponding to the first electrode 10 in the same electrode group 100 can be controlled by the same group of multiplexer (MUX) circuits.

[0096] And / or, the first input terminal A1 of the first driving circuit 20 to which the first electrode 10 is connected within the same electrode group 100 can be electrically connected.

[0097] It should be noted that when controlling the movement of the viewing window, the liquid crystal grating needs to achieve a variable period. Therefore, when the liquid crystal is deflected, the refractive index needs to exhibit a periodic change. By changing the potential of the first electrode 10, at least some of the first electrodes 10 within the electrode group 100 have different potentials, which can make the liquid crystal deflection angle at different positions different, thereby making the refractive index exhibit a periodic change.

[0098] For example, during the charging phase T1, the potentials of the data signals received by the first driving circuit 20 connected to the same electrode group 100 are different, which can make the potentials of at least some of the first electrodes 10 within the same electrode group 100 different.

[0099] For example, if the potential of the first signal connected to the first driving circuit 20 connected to the same electrode group 100 is different during the charging phase T1, it can make the potential of at least some of the first electrodes 10 in the same electrode group 100 different.

[0100] For example, the potential of the data signal accessed by the first driving circuit 20 connected to the same electrode group 100 is different during the charging phase T1, and the potential of the first signal accessed is also different, which can make the potential of at least some of the first electrodes 10 in the same electrode group 100 different.

[0101] In these examples, by forming different electrode groups 100 from multiple first electrodes 10, at least some of the first electrodes 10 within an electrode group 100 have different potentials, enabling the liquid crystal grating to achieve a variable period, which facilitates the control of window movement.

[0102] Please continue reading. Figure 3 , Figure 4 , Figure 6 as well as Figure 8 In some alternative examples, within an electrode group 100, the potential of the first electrode 10 arranged along the first direction X gradually increases or gradually decreases.

[0103] It should be noted that the driving cycle of the liquid crystal grating includes a first driving sub-cycle T3 and a second driving sub-cycle T4. The first driving sub-cycle T3 enables the movement of the first frame window, and the second driving sub-cycle T4 enables the movement of the second frame window. Within a single data write cycle of the first driving sub-cycle T3, the potential of the first electrode 10 arranged along the first direction X within the control electrode group 100 gradually increases, and within a single data write cycle of the second driving sub-cycle T4, the potential of the first electrode 10 arranged along the first direction X within the control electrode group 100 gradually decreases.

[0104] Within a single data write cycle of the first driving sub-cycle T3, the potential of the data signal corresponding to the first electrode 10 arranged along the first direction X within the control electrode group 100 gradually increases, and the first signal gradually increases, thereby allowing the potential of the first electrode 10 arranged along the first direction X to gradually increase.

[0105] Optionally, the potential of the first electrode arranged along the first direction X is non-linear.

[0106] For example, see Figure 4 During the first driving sub-cycle T3, the data signals received by the four first electrodes 10 arranged along the first direction X in the same electrode group 100 are V(1), V(2), V(3) and V(4), respectively, and the magnitudes of the received first signals are S(1), S(2), S(3) and S(4), respectively, where V(1) <V(2)<V(3)<V(4),S(1)<S(2)<S(3)<S(4)。

[0107] During a single data write cycle of the second driving sub-cycle T4, the potential of the data signal corresponding to the first electrode 10 arranged along the first direction X in the electrode group 100 can be gradually reduced, and the first signal can be gradually increased, thereby the potential of the first electrode 10 arranged along the first direction X can be gradually reduced.

[0108] For example, see Figure 4 During the second driving sub-cycle T4, the data signals received by the four first electrodes 10 arranged along the first direction X within the same electrode group 100 are V(1), V(2), V(3), and V(4), respectively, and the magnitudes of the received first signals are S(1), S(2), S(3), and S(4), respectively, where V(1)>V(2)>V(3)>V(4), and S(1)>V(4). <S(2)<S(3)<S(4)。

[0109] Alternatively, in other examples, the timing of the data signals in the first driving sub-cycle T3 and the second driving sub-cycle T4 can be swapped, which will not be elaborated on here.

[0110] In these examples, by setting the potential of the first electrode 10 arranged along the first direction X to gradually increase or gradually decrease within the same electrode group 100, the liquid crystal molecules controlled by the first electrode 10 can generate polarization and phase shift between the surface of the liquid crystal grating structure and the liquid crystal material according to the potential change of the first electrode 10, thus completing periodic deflection.

[0111] Please continue reading. Figure 4 Please refer to the following as well. Figure 6 and Figure 8In some alternative examples of the liquid crystal grating in this application, during the liquid crystal reset period, the reset signals Vrst received by two adjacent first electrodes 10 within an electrode group 100 are at different potentials.

[0112] The following example illustrates the concept of four first electrodes 10 within the same electrode group 100, i.e., n=4.

[0113] For example, within the same electrode group 100, the reset signals Vrst received by the four first electrodes 10 arranged along the first direction X are, in sequence, a positive reset signal, a negative reset signal, a positive reset signal, and a negative reset signal.

[0114] For example, within the same electrode group 100, the reset signals Vrst received by the four first electrodes 10 arranged along the first direction X are, in sequence, a negative reset signal, a positive reset signal, a negative reset signal, and a positive reset signal.

[0115] It should be noted that during the liquid crystal operation phase T6, prior to the liquid crystal reset phase T7, the liquid crystal is controlled by the different potentials of multiple first electrodes 10, forming a longitudinal electric field. This causes the liquid crystal to deflect periodically, and the liquid crystal molecules are in a non-initial state. To ensure accurate window movement in the next phase, the liquid crystal reset phase T7 is established. When applying a reset signal Vrst to the first electrode 10, if the potentials of the reset signals Vrst received by adjacent first electrodes 10 are the same, it can easily lead to ion accumulation in the liquid crystal, affecting the display effect of the holographic 3D display device where the final liquid crystal grating is located. By making the potentials of the reset signals Vrst received by adjacent first electrodes 10 different, a lateral electric field is provided to reset the liquid crystal molecules, thus improving the resulting liquid crystal ion accumulation and indirectly enhancing the display effect of the holographic 3D display device.

[0116] Please refer to Figures 6 to 8 In some alternative examples of the liquid crystal grating in this application, the reset module 23 is electrically connected to N first driving circuits 20, where N≥1 and N is a positive integer.

[0117] For example, please see Figure 6 The reset module 23 can be electrically connected to the first drive circuit 20 one-to-one. This ensures that the reset signal Vrst can be accurately output to the first electrode 10 through the first drive circuit 20, thereby achieving precise reset of the potentials of the multiple first electrodes 10.

[0118] Please refer to Figure 8 The reset module 23 can also be electrically connected to multiple first drive circuits 20. By reusing the reset module 23, the overall layout area of ​​the reset module 23 can be reduced in the panel layout, saving panel space.

[0119] For example, still using the electrode group 100 described above, which includes four first electrodes 10, one reset module 23 can be electrically connected to an odd number of first driving circuits 20 arranged along the first direction X. Through these first driving circuits 20, a positive reset signal Vrst or a negative reset signal Vrst can be transmitted to the corresponding first electrode 10. Another reset module 23 can be electrically connected to an even number of first driving circuits 20 arranged along the first direction X. Through these first driving circuits 20, a negative reset signal Vrst or a positive reset signal Vrst can be provided to the corresponding first electrode 10.

[0120] Please refer to Figure 9 and Figure 10 In some alternative embodiments of the liquid crystal grating in this application, the liquid crystal grating further includes a first substrate P1, a second substrate P2 and a liquid crystal layer P3; the liquid crystal layer P3 is located between the first substrate P1 and the second substrate P2.

[0121] A plurality of first electrodes 10 are formed on the side of the first substrate P1 or the second substrate P2 near the liquid crystal layer P3. The first electrodes 10 are electrically connected to the first switching unit 21 and the first electrode plate J1 in the first driving circuit 20. In addition, a second electrode 11 is also provided on the first substrate P1 or the second substrate P2.

[0122] The second electrode 11 can be a common electrode. The second electrode 11 can be located on the same substrate as the first electrode 10. For example, both the first electrode 10 and the second electrode 11 can be located on the first substrate P1, or both the first electrode 10 and the second electrode 11 can be located on the second substrate P2. Exemplarily, the first electrode 10 and the second electrode 11 can also be disposed in the same layer.

[0123] The first electrode 10 can also be formed on the first substrate P1, and the second electrode 11 can be formed on the second substrate P2.

[0124] In this example, the relative positions of the first electrode 10 and the second electrode 11 are given. An electric field is formed by the cooperation of the first electrode 10 and the second electrode 11 to achieve the deflection adjustment of the liquid crystal.

[0125] Please refer to Figure 4 , Figure 10 and Figure 11 In some alternative examples of the liquid crystal grating in this application, the liquid crystal grating further includes a second driving circuit 30, which includes a storage unit Cst, a first switching unit 21 and a second switching unit 22, and a reset unit 24.

[0126] In the second driving circuit 30, the first input terminal A1 of the first switching unit 21 receives a data signal, and the second input terminal B1 of the second switching unit 22 receives a first signal.

[0127] The storage unit Cst includes a first electrode J1 and a second electrode J2. The first electrode J1 is electrically connected to the first electrode 10 and is also electrically connected to the first output terminal A2 of the first switching unit 21. The second electrode J2 is electrically connected to the second output terminal B2 of the second switching unit 22.

[0128] The output terminal of the aforementioned reset unit 24 is connected to the second electrode plate J2, and the input terminal of the reset unit 24 receives a third level signal.

[0129] During the charging phase T1 of a driving cycle of the liquid crystal grating, the second switching unit 22 in the second driving circuit 30 transmits a first level signal to the second electrode J2.

[0130] During the charge pumping phase T2 of a driving cycle of the liquid crystal grating, the reset unit 24 transmits a third-level signal to the second electrode J2; the potentials of the first-level signal and the third-level signal are different.

[0131] It should be noted that in this example, a portion of the first electrode 10 is electrically connected to the first driving circuit 20 and a portion of the first electrode 10 is electrically connected to the second driving circuit 30 in the liquid crystal grating. The first driving circuit 20 provides a driving signal to a portion of the first electrode 10, and the second driving circuit 30 provides a driving signal to the other portion of the first electrode 10.

[0132] The main difference between the second driving circuit 30 and the first driving circuit 20 is that the second driving circuit 30 includes a reset unit 24. Specifically, for the first electrode 10 connected to the second driving circuit 30, the reset unit 24 controls the second plate J2 of the storage unit Cst to reset its potential during the charge pumping stage T2; for the first electrode 10 connected to the first driving circuit 20, the first signal line S performs a phase change to achieve the potential reset of the second plate J2 during the charge pumping stage T2.

[0133] In contrast, by replacing part of the second driving circuit 30 with the first driving circuit 20 in the liquid crystal grating, the setting of the reset unit 24 is reduced, which can reduce the area of ​​the reset unit 24 and the metal traces related to the reset unit 24 in the driving circuit, reduce the bezel ratio of the holographic three-dimensional display device where the liquid crystal grating is located, and indirectly increase the storage capacity of the storage unit Cst in the first driving circuit 20.

[0134] Please refer to Figure 12 Please refer to the following as well. Figures 10 to 11 Based on the above examples, in some alternative examples of the liquid crystal grating in this application, the storage capacity of the storage cell Cst in the first driving circuit 20 is greater than the storage capacity of the storage cell Cst in the second driving circuit 30.

[0135] The aforementioned storage unit Cst can be a capacitor with a first plate J1 and a second plate J2, and the storage capacity is the capacitance value.

[0136] It should be noted that a first driving circuit 20 is set in the liquid crystal grating. Compared with the second driving circuit 30 of the liquid crystal grating, the state of the second switching unit 22 and the timing of the first signal are changed during the charge pumping stage T2. That is, the first signal is reused, which replaces the function of the reset unit 24 in the second driving circuit 30. This can reduce the area of ​​the reset unit 24 and the metal traces related to the reset unit 24 in the driving circuit, thereby improving the charging performance of the first electrode 10. The original position of the reset unit 24 can be used to increase the positive projection area of ​​the storage unit Cst along the positive projection direction of the liquid crystal grating. That is, the storage capacity of the storage unit Cst in the first driving circuit 20 is greater than the storage capacity of the storage unit Cst in the second driving circuit 30, thus improving the charging performance of the liquid crystal grating.

[0137] The above text combines Figures 1 to 12 The present application describes in detail the liquid crystal grating according to the embodiments of the present application. The present application also provides a holographic three-dimensional display device, which includes a liquid crystal grating configured as described in the above embodiments. Therefore, the holographic three-dimensional display device provided by the present application has all the beneficial effects of the liquid crystal grating embodiments described above.

[0138] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0139] It should be understood that in the embodiments of this application, "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean that B is determined solely based on A; B can also be determined based on A and / or other information.

[0140] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A liquid crystal grating, characterized in that, include: Multiple first electrodes; A first driving circuit provides a driving signal to the first electrode; The first driving circuit includes: A first switching unit and a second switching unit, wherein the first input terminal of the first switching unit receives a data signal and the second input terminal of the second switching unit receives a first signal; The storage unit includes a first electrode plate and a second electrode plate. The first electrode plate is electrically connected to the first electrode and is also electrically connected to the first output terminal of the first switching unit. The second electrode plate is electrically connected to the second output terminal of the second switching unit. One driving cycle of the liquid crystal grating includes a charging phase and a charge pumping phase; During the charging phase, the first switching unit is turned on, the second switching unit is turned on, the first switching unit transmits a data signal to the first electrode plate, and the second switching unit transmits a first level signal to the second electrode plate. During the charge pumping phase, the first switching unit is turned off, the second switching unit is turned on, and the second switching unit transmits a second level signal to the second electrode. The first level signal and the second level signal have different potentials. The second level signal is used as a reset signal to reset the second electrode of the storage unit, so that the storage unit can pump the raised charging voltage to the first electrode by taking advantage of the characteristic that the voltage between its two electrodes cannot change instantaneously.

2. The liquid crystal grating according to claim 1, characterized in that, The first switching unit includes a first control terminal; the second switching unit includes a second control terminal. The first input terminal is electrically connected to the data signal line, the first output terminal is electrically connected to the first electrode and the first plate respectively, and the first control terminal is electrically connected to the first control signal line. The second input terminal is electrically connected to the first signal line, the second output terminal is electrically connected to the second electrode plate, and the second control terminal is electrically connected to the second control signal line.

3. The liquid crystal grating according to claim 2, characterized in that, During the charge pumping phase, the first control terminal turns off the first switching unit in response to the non-enable signal output from the first control signal line, and the second control terminal turns on the second switching unit in response to the enable signal output from the second control signal line.

4. The liquid crystal grating according to claim 2, characterized in that, During the charging phase, the first control terminal turns on the first switching unit in response to the enable signal output from the first control signal line, and the second control terminal turns on the second switching unit in response to the enable signal output from the second control signal line.

5. The liquid crystal grating according to claim 2, characterized in that, The first switching unit includes a first transistor, and the second switching unit includes a second transistor; The first transistor and the second transistor are of different types; The input terminal of the first transistor is the first input terminal, the output terminal of the first transistor is the first output terminal, and the control terminal of the first transistor is the first control terminal; The input terminal of the second transistor is the second input terminal, the output terminal of the second transistor is the second output terminal, and the control terminal of the second transistor is the second control terminal.

6. The liquid crystal grating according to claim 5, characterized in that, The first transistor is a polycrystalline silicon thin-film transistor, and the second transistor is an oxide thin-film transistor.

7. The liquid crystal grating according to claim 1, characterized in that, The liquid crystal grating further includes: The reset module includes a third input terminal, a third output terminal, and a third control terminal; The third input terminal receives a reset signal, the third output terminal is electrically connected to the first electrode, and the third control terminal is electrically connected to the third control signal line.

8. The liquid crystal grating according to claim 7, characterized in that, A driving cycle of the liquid crystal grating includes a first driving sub-cycle and a second driving sub-cycle. Both the first driving sub-cycle and the second driving sub-cycle include a data writing stage, a liquid crystal running stage, and a liquid crystal reset stage. The data writing phase includes multiple data writing cycles, and the data writing cycle includes the charging phase and the charge pumping phase.

9. The liquid crystal grating according to claim 8, characterized in that, During the liquid crystal reset phase, the third control terminal activates the reset module in response to the enable signal transmitted by the third control signal line.

10. The liquid crystal grating according to claim 8, characterized in that, The plurality of first electrodes form different electrode groups, and at least some of the first electrodes in a group of electrodes have different potentials.

11. The liquid crystal grating according to claim 10, characterized in that, Within the electrode group, the potential of the first electrode arranged along the first direction gradually increases or gradually decreases.

12. The liquid crystal grating according to claim 10, characterized in that, During the liquid crystal reset period, the potentials of the reset signals received by two adjacent first electrodes within one electrode group are different.

13. The liquid crystal grating according to claim 7, characterized in that, The reset module is electrically connected to N of the first drive circuits, where N ≥ 1 and N is a positive integer.

14. The liquid crystal grating according to claim 6, characterized in that, The liquid crystal grating further includes a first substrate, a second substrate, and a liquid crystal layer; the liquid crystal layer is located between the first substrate and the second substrate. A plurality of first electrodes are formed on the side of the first substrate or the second substrate near the liquid crystal layer, and the first electrodes are electrically connected to the first switching unit and the first electrode plate in the first driving circuit. A second electrode is also disposed on the first substrate or the second substrate.

15. The liquid crystal grating according to claim 1, characterized in that, The liquid crystal grating further includes a second driving circuit, which includes a storage unit, a first switching unit, and a second switching unit. The second driving circuit also includes a reset unit. In the second driving circuit, the first input terminal of the first switching unit receives a data signal, and the second input terminal of the second switching unit receives a first signal; The storage unit includes a first electrode plate and a second electrode plate. The first electrode plate is electrically connected to the first electrode and is also electrically connected to the first output terminal of the first switching unit. The second electrode plate is electrically connected to the second output terminal of the second switching unit. The output terminal of the reset unit is connected to the second electrode plate, and the input terminal of the reset unit receives a third level signal; During the charging phase, the second switching unit in the second driving circuit transmits a first level signal to the second electrode plate; During the charge pumping phase, the reset unit transmits a third-level signal to the second electrode plate; the first-level signal and the third-level signal have different potentials.

16. The liquid crystal grating according to claim 15, characterized in that, The storage capacity of the storage unit in the first driving circuit is greater than the storage capacity of the storage unit in the second driving circuit.

17. A holographic three-dimensional display device, characterized in that, include: A liquid crystal grating, wherein the liquid crystal grating is configured as a liquid crystal grating as described in claims 1 to 16.

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