Liquid crystal grating and holographic display device

Abstract

The present invention discloses a liquid crystal grating and a holographic display device, relating to the technical field of holographic display. The liquid crystal grating includes a plurality of grating electrode groups, and one grating electrode group includes a plurality of grating electrodes; the working states of the liquid crystal grating include a first mode and a second mode. In the first mode, a first voltage with a first polarity is provided to the grating electrodes. For one grating electrode group, the average voltage value of the first voltage is |V1|; in the second mode, a second voltage with a second polarity is provided to the grating electrodes. For one grating electrode group, the average voltage value of the second voltage is |V2|; wherein, the first polarity is different from the second polarity, and |V1| < |V2|; the number of the first mode is N1, and the number of the second mode is N2; wherein, N1 > N2, and N1 and N2 are positive integers. In the embodiment provided by the present invention, by limiting the number of the first mode and the second mode within one working cycle of the liquid crystal grating, the components of the voltages with different polarities are made to approach the same.

Description

Technical Field

[0001] The present invention relates to the technical field of holographic display, and more specifically, to a liquid crystal grating and a holographic display device. Background Art

[0002] Since two-dimensional displays cannot clearly and accurately express three-dimensional depth information, people have been committed to researching display technology that can display three-dimensional scenes, that is, holographic (3D) displays.

[0003] In the prior art, when a holographic display device displays a three-dimensional image, after the spatial light modulator modulates the phase and amplitude of the light, a liquid crystal grating is used to form a left-eye image and a right-eye image. In an ideal state, the liquid crystal has the same response to positive and negative voltages of the same amplitude. However, the liquid crystal has additional polarization due to deformation, resulting in different responses to positive and negative voltages of the same amplitude, that is, electrical bending. In order to ensure that the degree of deflection is the same when positive and negative voltages are applied to the liquid crystal, the amplitudes of the positive and negative voltages need to be different. However, after long-term use, the liquid crystal will gather to one side, forming an afterimage, which affects the display effect. Summary of the invention

[0004] In view of this, the present invention provides a liquid crystal grating and a holographic display device, which can eliminate afterimages and improve display effects.

[0005] In a first aspect, the present invention provides a liquid crystal grating, comprising a plurality of grating electrode groups, wherein one of the grating electrode groups comprises a plurality of grating electrodes;

[0006] The working state of the liquid crystal grating includes a first mode and a second mode,

[0007] In the first mode, a first voltage of a first polarity is provided to the grating electrode, and for one grating electrode group, an average voltage value of the first voltage is |V1|;

[0008] In the second mode, a second voltage of a second polarity is provided to the grating electrode, and for one grating electrode group, an average voltage value of the second voltage is |V2|;

[0009] The first polarity is different from the second polarity, and |V1|<|V2|;

[0010] In one working cycle of the liquid crystal grating, light is modulated by the liquid crystal grating to obtain deflected light, and the liquid crystal grating switches between the first mode and the second mode, the number of the first modes is N1, and the number of the second modes is N2;

[0011] Wherein, N1>N2, and N1 and N2 are positive integers.

[0012] In a second aspect, the present invention provides a holographic display device, comprising the liquid crystal grating provided in the first aspect of the present invention.

[0013] Compared with the prior art, the liquid crystal grating and holographic display device provided by the present invention achieve at least the following beneficial effects:

[0014] In the embodiment provided by the present invention, the number of the first mode and the second mode is limited within one working cycle of the liquid crystal grating. Specifically, for the first mode and the second mode with different polarities of the voltage provided to the liquid crystal grating, if the average voltage value |V1| of the first voltage provided to the grating electrode group in the first mode is less than the average voltage value |V2| of the second voltage provided to the grating electrode group in the second mode, then in one working cycle of the liquid crystal grating, the number of the first mode N1 is greater than the number of the second mode N2, so that the components of the voltages of different polarities are close to the same within one working cycle. The embodiment provided by the present invention does not need to change the original physical structure or circuit structure of the liquid crystal grating, and can achieve the avoidance of the occurrence of afterimages and improve the display effect, which is simpler and more convenient.

[0015] Of course, any product implementing the present invention does not necessarily need to achieve all of the technical effects described above at the same time.

[0016] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0018] Figure 1 A schematic diagram of the structure of a liquid crystal grating provided in an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of another liquid crystal grating structure provided by an embodiment of the present invention;

[0020] Figure 3 A diagram of an application scenario of a liquid crystal grating provided by an embodiment of the present invention;

[0021] Figure 4 A timing diagram of the liquid crystal grating provided by an embodiment of the present invention;

[0022] Figure 5 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention;

[0023] Figure 6 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention;

[0024] Figure 7 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention;

[0025] Figure 8 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention;

[0026] Fig. 9 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention;

[0027] Fig.10 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention;

[0028] Fig.11 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention;

[0029] Fig.12 A schematic structural diagram of a holographic display device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0031] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0032] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0033] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0034] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0035] In the prior art, when a holographic display device displays a three-dimensional image, after the spatial light modulator modulates the phase and amplitude of the light, a liquid crystal grating is used to form a left-eye image and a right-eye image. In an ideal state, the liquid crystal has the same response to positive and negative voltages of the same amplitude. However, the liquid crystal has additional polarization due to deformation, resulting in different responses to positive and negative voltages of the same amplitude, that is, electrical bending. In order to ensure that the degree of deflection is the same when positive and negative voltages are applied to the liquid crystal, the amplitudes of the positive and negative voltages need to be different. However, after long-term use, the liquid crystal will gather to one side, forming an afterimage, which affects the display effect.

[0036] In order to solve the above technical problems, the embodiment of the present invention provides a liquid crystal grating, referring to Figure 1 As shown, Figure 1 The present invention provides a schematic diagram of the structure of a liquid crystal grating according to an embodiment of the present invention. The present invention provides a liquid crystal grating 100, including a plurality of grating electrode groups 10, wherein one grating electrode group includes a plurality of grating electrodes 01; the working state of the liquid crystal grating 100 includes a first mode and a second mode.

[0037] In the first mode, a first voltage of a first polarity is provided to the grating electrode 01, and for one grating electrode group 10, an average voltage value of the first voltage is |V1|;

[0038] In the second mode, a second voltage of a second polarity is provided to the grating electrode 01, and for one grating electrode group 10, an average voltage value of the second voltage is |V2|;

[0039] The first polarity is different from the second polarity, and |V1|<|V2|;

[0040] In a working cycle T of the liquid crystal grating 100, light is modulated by the liquid crystal grating 100 to obtain deflected light, and the liquid crystal grating 100 switches between a first mode and a second mode. The number of first modes is N1, and the number of second modes is N2; wherein N1>N2, and N1 and N2 are positive integers.

[0041] The liquid crystal grating 100 includes a common electrode 20 and a grating electrode 01 facing each other. Liquid crystal 30 is filled between the common electrode 20 and the grating electrode 01. A common voltage is applied to the common electrode 20, and a driving voltage is applied to the grating electrode 01. The electric field formed by the common electrode 20 and the grating electrode 01 can drive the liquid crystal to deflect, thereby deflecting the light incident on the liquid crystal grating 100 to different directions.

[0042] In the embodiment provided by the present invention, the liquid crystal grating 100 includes a plurality of grating electrode groups 10 arranged in sequence along a direction parallel to the light emitting surface of the liquid crystal grating 100, and one grating electrode group 10 includes a plurality of grating electrodes 01. Specifically, the first mode refers to providing a voltage of a first polarity to the liquid crystal grating 100, and the second mode refers to providing a voltage of a second polarity to the liquid crystal grating 100. The first polarity and the second polarity are different. Exemplarily, the first polarity is positive and the second polarity is negative; conversely, the first polarity is negative and the second polarity is positive. Therefore, the first mode and the second mode refer to the deflection of the liquid crystal 30 under the action of the electric field formed by the positive voltage or the negative voltage.

[0043] In the first mode, a first voltage of a first polarity is provided to the grating electrode 01. In the same grating electrode group 10, the voltage values ​​of the first voltage to multiple grating electrodes 01 are different. In an optional embodiment, multiple grating electrodes 01 in one grating electrode group 10 are loaded with a gradient voltage. For the grating electrode group 10, the average voltage value of the first voltage is |V1|. Similarly, in the second mode, a second voltage of a second polarity is provided to the grating electrode 01, and the voltage values ​​of the second voltage of each grating electrode 01 are different. In the same grating electrode group 10, the average voltage value of the second voltage is |V2|. And |V1|<|V2|.

[0044] In one case, the deflection direction of the liquid crystal 30 in the first mode and the second mode is the same, and the electric bending affects the deflection direction of the liquid crystal 30 in the liquid crystal grating 100. When voltages of different polarities are applied to the grating electrode 01, the amplitude of the voltage should be different. That is, the average voltage value |V1| of the first voltage provided to the grating electrode group 10 in the first mode is smaller than the average voltage value |V2| of the second voltage provided to the grating electrode group 10 in the second mode. In another case, the deflection direction of the liquid crystal 30 in the first mode and the second mode is different, and the external electric fields of different strengths make the deflection angles of the liquid crystal 30 different. Generally, the average voltage value |V1| of the first voltage provided to the grating electrode group 10 in the first mode is also smaller than the average voltage value |V2| of the second voltage provided to the grating electrode group 10 in the second mode.

[0045] The liquid crystal grating 100 has a plurality of working cycles T. In one working cycle T, the liquid crystal grating 100 switches between the first mode and the second mode, and the number of the first mode is N1, and the number of the second mode is N2; N1>N2, and N1 and N2 are positive integers. In the embodiment provided by the present invention, the average voltage values ​​of the voltages of the first mode and the second mode are both in the relationship of |V1|<|V2|, therefore, the relationship between the number of the first mode and the second mode is designed to be N1>N2. In this way, in a complete working cycle T of the liquid crystal grating 100, the components of the positive voltage and the negative voltage provided to the liquid crystal grating 100 are close to the same, thereby achieving DC balance, avoiding the liquid crystal from gathering to one side, forming afterimages, and affecting the display effect.

[0046] It should be noted that the duration of a working cycle T of the liquid crystal grating 100 can be set according to the actual application scenario. For example, if the duration of the first mode and the second mode is 1 frame, and |V1|=2V, |V2|=3V, then a working cycle T can be set to 5 frames, where the number of first modes is 3 and the number of second modes is 2. In another example, the duration of the first mode and the second mode is also 1 frame, and |V1|=4V, |V2|=7V, then a working cycle T can be set to 11 frames, where the number of first modes is 7 and the number of second modes is 4.

[0047] In the embodiment provided by the present invention, the number of the first mode and the second mode is limited within a working cycle T of the liquid crystal grating 100. Specifically, for the first mode and the second mode with different polarities of the voltage provided to the liquid crystal grating 100, if the average voltage value |V1| of the first voltage provided to the grating electrode group 10 in the first mode is less than the average voltage value |V2| of the second voltage provided to the grating electrode group 10 in the second mode, then in a working cycle T of the liquid crystal grating 100, the number N1 of the first mode is greater than the number N2 of the second mode, so that the components of the voltages of different polarities in one working cycle T are close to the same, thereby achieving DC balance. The embodiment provided by the present invention does not need to change the original physical structure or circuit structure of the liquid crystal grating 100, and can avoid the occurrence of afterimages and improve the display effect, which is simpler and more convenient.

[0048] In another optional embodiment provided by the present invention, |V1|, |V2|, N1, and N2 satisfy:

[0049]

[0050] Wherein, m is the first correction coefficient, 0.8≤m≤1.2.

[0051] |V1| refers to the average voltage value of the first voltage provided to the liquid crystal grating 100 in the first mode; |V2| refers to the average voltage value of the second voltage provided to the liquid crystal grating 100 in the second mode; N1 refers to the number of first modes in one working cycle T of the liquid crystal grating 100; N2 refers to the number of second modes in one working cycle T of the liquid crystal grating 100.

[0052] It can be used to indicate the degree of difference between the first mode and the second mode. Exemplarily, if |V1N1|=2|V2N2|, then in the first mode, the product of the average voltage value of the first voltage and the number of the first mode is greater than the product of the average voltage value of the second voltage and the number of the second mode in the second mode. In other words, the bias of the voltage of the first polarity provided to the liquid crystal grating 100 is greater than the bias of the voltage of the second polarity provided to the liquid crystal grating 100. In long-term use, DC imbalance will result.

[0053] Therefore, in the embodiments provided by the present invention, m is the first correction coefficient, 0.8≤m≤1.2. That is, in one working cycle T, 0.8|V2N2|≤|V1N1|≤1.2|V2N2|, so that the difference between |V1N1| and |V2N2| is controlled within a certain range. Since the duration of one working cycle T of the liquid crystal grating 100 is set according to the actual application scenario, In the example, if |V1| is less than |V2|, then N1 is greater than N2. Moreover, the greater the difference between |V1| and |V2|, the greater the difference between N1 and N2; the smaller the difference between |V1| and |V2|, the smaller the difference between N1 and N2. For example, if |V1|=3V, |V2|=2V, then N1=3, N2=2; if |V1|=4V, |V2|=7V, then N1=7, N2=4.

[0054] In the embodiment provided by the present invention, the quantitative relationship between |V1|, |V2|, N1, and N2 is expressed by Determine, where 0.8≤m≤1.2. In practical applications, |V1| and |V2| are known, so the ratio of N1 and N2 can be determined based on the value of m. In practical applications, since N1 and N2 are positive integers, is a numerical range. Of course, the closer m is to 1, the higher the DC balance of the liquid crystal grating 100 is, and the closer m is to 0.8 or 1.2, the lower the DC balance of the liquid crystal grating 100 is. When m is less than 0.8 or greater than 1.2, it indicates that the DC of the liquid crystal grating 100 is unbalanced, and it is necessary to redefine the duration of a working cycle T of the liquid crystal grating 100 and the values ​​of N1 and N2. The embodiment provided by the present invention further defines the quantitative relationship between |V1|, |V2|, N1, and N2, so that when voltages of different polarities are provided to the liquid crystal grating 100, it can approach DC balance.

[0055] In another optional embodiment provided by the present invention, the first correction coefficient m=1.

[0056] In the embodiment provided by the present invention, m=1, in other words, Or |V1N1|=|V2N2|. At this time, the component of the first voltage of the first polarity provided to the liquid crystal grating 100 is the same as the component of the second voltage of the second polarity, so that DC balance can be achieved within a working cycle T of the liquid crystal grating 100, afterimages can be eliminated, and display effects can be improved.

[0057] In another optional embodiment provided by the present invention, |V1|, |V2|, N1, and N2 satisfy:

[0058]

[0059] Wherein, n is the second correction coefficient, n≤0.5.

[0060] |V1| refers to the average voltage value of the first voltage provided to the liquid crystal grating 100 in the first mode; |V2| refers to the average voltage value of the second voltage provided to the liquid crystal grating 100 in the second mode; N1 refers to the number of first modes in one working cycle T of the liquid crystal grating 100; N2 refers to the number of second modes in one working cycle T of the liquid crystal grating 100.

[0061] It can be used to indicate the degree of difference between the first mode and the second mode. Where |V1|<|V2|, and N1>N2, therefore, and Both are greater than 0 and less than 1. The smaller the value, the greater the difference between the average voltage value of the first voltage provided to the liquid crystal grating 100 in the first mode and the average voltage value of the second voltage provided to the liquid crystal grating 100 in the second mode. Therefore, in order to compensate for the component of the voltage of the first polarity, it is necessary to make the number of the first mode N1 greater than the number of the second mode N2, and and There is a positive correlation.

[0062] In the embodiments provided by the present invention, And n≤0.5. In other words, and In this way, it can be ensured that the number N1 of the first modes can compensate for the DC imbalance caused by the average voltage value of the first voltage being less than the average voltage value of the second voltage, and the number N2 of the second modes can suppress the DC imbalance caused by the average voltage value of the second voltage being greater than the average voltage value of the first voltage.

[0063] In an optional implementation, n=0, then That is, |V1N1|=|V2N2|. At this time, in the first mode, the component of the first voltage of the first polarity provided to the liquid crystal grating 100 is the same as the component of the second voltage of the second polarity provided to the liquid crystal grating 100 in the second mode, which can achieve DC balance of the liquid crystal grating 100, eliminate afterimages, and improve display effects.

[0064] In another optional embodiment provided by the present invention, referring to Figure 2 As shown, Figure 2 A schematic diagram of another structure of a liquid crystal grating provided by an embodiment of the present invention. Along the arrangement direction of the grating electrodes 01, the amplitudes of the potentials of the multiple grating electrodes 01 in the same grating electrode group 10 increase sequentially;

[0065] The average voltage of the grating electrode group 10 is the arithmetic average of the amplitudes of the potentials of the plurality of grating electrodes 01 included in the grating electrode group 10 .

[0066] The external electric field formed by the common electrode 20 and the grating electrode 01 can polarize the liquid crystal 30 and drive the liquid crystal 30 to rotate. Generally speaking, the common electrode 20 is an integral electrode plate, and a common voltage is provided to the common electrode 20. The grating electrodes 01 opposite to the common electrode 20 include multiple ones, and are arranged in a direction parallel to the light-emitting surface of the liquid crystal grating 100. The driving of the multiple grating electrodes 01 is independent of each other. Therefore, when different driving voltages are provided to different grating electrodes 01, the electric fields formed between them and the common electrode 20 are different. The deflection angles of the liquid crystal 30 filled between the grating electrode 01 and the common electrode 20 are also different.

[0067] Therefore, along the arrangement direction of the grating electrodes 01, the amplitudes of the potentials of the multiple grating electrodes 01 in the same grating electrode group 10 increase sequentially. In other words, in the same grating electrode group 10, the amplitudes of the potentials of the grating electrodes 01 increase sequentially, and the intensity of the external electric field formed between the grating electrodes 01 and the common electrode 20 gradually increases. Furthermore, the deflection angle of the liquid crystal 30 filled between the grating electrode 01 and the common electrode 20 gradually increases.

[0068] For the same grating electrode group 10 , the deflection angle of the liquid crystal 30 gradually increases, and the liquid crystal 30 corresponding to the grating electrode group 10 forms a prism structure, which can deflect the incident light.

[0069] Since the amplitudes of the potentials of the multiple grating electrodes 01 in the same grating electrode group 10 increase sequentially, the average voltage of the grating electrode group 10 is the arithmetic mean of the amplitudes of the potentials of the multiple grating electrodes 01 in the grating electrode group 10. The arithmetic mean here refers to adding the amplitudes of the potentials of the multiple grating electrodes 01 in the grating electrode group 10 and then dividing by the number of grating electrodes 01. The arithmetic mean is used to indicate the average level of the potential of the grating electrode group 10, so as to measure the magnitude of the voltages of different polarities provided to the liquid crystal grating 100. Then, the number of the first mode and the second mode of different polarities provided to the liquid crystal grating 100 is designed by the magnitude of the voltages of different polarities.

[0070] Since the DC balance is determined over a certain period of time for the entire liquid crystal grating 100, the average voltage of the grating electrode group 10 can be used to refer to the voltage of the grating electrode group 10 at this moment.

[0071] In the embodiment provided by the present invention, by providing a potential with gradually increasing amplitude to the grating electrode 01 of the same grating electrode group 10, the grating electrode group 10 forms a prism structure, thereby being able to deflect the incident light. The light deflected in different directions forms a left eye pattern and a right eye image respectively, thereby achieving a holographic display effect.

[0072] In another optional embodiment provided by the present invention, referring to Figure 3 and Figure 4 As shown, Figure 3 This is an application scenario diagram of a liquid crystal grating provided by an embodiment of the present invention. Figure 4 A timing diagram of the liquid crystal grating provided by the embodiment of the present invention. The working state of the liquid crystal grating 100 is that the first mode and the second mode are arranged alternately.

[0073] In the embodiment provided by the present invention, the liquid crystal grating 100 is switched between a first mode and a second mode. In the first mode, a first voltage of a first polarity is provided to the liquid crystal grating 100; in the second mode, a second voltage of a second polarity is provided to the liquid crystal grating 100.

[0074] Reference Figure 4 As shown, the average voltage value |V1| of the first voltage of the first polarity in the first mode is less than the average voltage value |V2| of the second voltage of the second polarity in the second mode. Therefore, Figure 4The figure shows a working cycle T of the liquid crystal grating 100. In a working cycle T, the number of first modes is 3, and the number of second modes is 2. The quantitative relationship between the first mode and the second mode is inversely correlated with the average voltage value. A triangle represents a grating electrode group loaded with a gradient voltage. The inclined side of the triangle represents the relative magnitude relationship of the voltages in the grating electrode group, which does not mean that the voltage magnitude relationship is linear. The horizontal axis can be understood as the spatial position of the grating electrode; the figure only illustrates that a liquid crystal grating includes three grating electrode groups, but in actual application, there can be more grating electrode groups, depending on the specific situation. In each grating electrode group, the number of grating electrodes can be the same or different. The three grating electrode groups are loaded with gradient voltages in turn, and the liquid crystal is deflected under the action of the electric field, modulating the light incident on the liquid crystal grating.

[0075] In one working cycle T of the liquid crystal grating 100, the first mode and the second mode are arranged alternately. That is, the liquid crystal grating 100 is alternately provided with voltages of the first polarity and the second polarity. The voltages of different polarities are arranged alternately, which can avoid excessive accumulation of the components of the voltage of the first polarity or the voltage of the second polarity in a short time, thereby causing DC imbalance in a short time.

[0076] It should be noted that a working cycle T of the liquid crystal grating 100 includes multiple time periods. Figure 4 During the one period shown, a voltage of one polarity is provided to the liquid crystal grating 100. In addition, Figure 4 It is only used to indicate the change trend of the potential of multiple grating electrodes 01 in a grating electrode group 10, and does not represent the actual voltage value. Figure 4 The minimum voltage in the figure is 0V, which is also only for illustration. In the actual scheme, the minimum voltage value can be selected according to the actual situation. In addition, the increase and decrease of the voltage amplitude of the gradient voltage in a grating electrode group 10 are nonlinear. Figure 4 It is only used to illustrate the voltage relationship, not a linear relationship.

[0077] In another optional embodiment provided by the present invention, referring to Figure 5 As shown, Figure 5 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention. The working state of the liquid crystal grating 100 is that a plurality of first modes are arranged adjacent to each other, and a plurality of second modes are arranged adjacent to each other.

[0078] In the embodiment provided by the present invention, the liquid crystal grating 100 is switched between a first mode and a second mode. In the first mode, a first voltage of a first polarity is provided to the liquid crystal grating 100; in the second mode, a second voltage of a second polarity is provided to the liquid crystal grating 100.

[0079] Reference Figure 5 As shown, the average voltage value |V1| of the first voltage of the first polarity in the first mode is less than the average voltage value |V2| of the second voltage of the second polarity in the second mode. Therefore, Figure 5 The figure shows a working cycle T of the liquid crystal grating 100. In the working cycle T, the number of the first modes is 3, and the number of the second modes is 2. The relationship between the number of the first modes and the second modes is inversely correlated with the average voltage value.

[0080] In a working cycle T of the liquid crystal grating 100, a plurality of first modes are adjacent and a plurality of second modes are adjacent. That is, in a relatively short time, a voltage of the same polarity is provided to the liquid crystal grating 100. The voltages of the same polarity are arranged in sequence, which can reduce the number of changes in the polarity of the driving voltage, thereby improving the driving efficiency of the liquid crystal grating 100.

[0081] It should be noted that a working cycle T of the liquid crystal grating 100 includes multiple time periods. Figure 5 During the one period shown, a voltage of one polarity is provided to the liquid crystal grating 100. In addition, Figure 5 It is only used to indicate the change trend of the potential of multiple grating electrodes 01 in a grating electrode group 10, and does not represent the actual voltage value. Figure 5 The minimum voltage in the figure is 0V, which is also only for illustration. In the actual scheme, the minimum voltage value can be selected according to the actual situation. In addition, the increase and decrease of the voltage amplitude of the gradient voltage in a grating electrode group 10 are nonlinear. Figure 5 It is only used to illustrate the voltage relationship, not a linear relationship.

[0082] In another optional embodiment provided by the present invention, referring to Figure 6 As shown, Figure 6 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention. The working cycle T includes N total display frames TF; wherein N=N1+N2; the total display frame TF includes at least the first color frame R1;

[0083] In the first color frame R1, the first type of light is modulated by the liquid crystal grating 100 to obtain the first deflected light;

[0084] In a working cycle T of the liquid crystal grating 100, in at least one first color frame R1, the working state of the liquid crystal grating 100 is the first mode ( Figure 6 In the figure, + represents the first mode), and in at least one first color frame R1, the working state of the liquid crystal grating 100 is the second mode ( Figure 6 - is used to indicate the second mode).

[0085] One working cycle T of the liquid crystal grating 100 includes N total display frames TF, wherein the total display frames TF are used to provide a display picture. Specifically, one display picture includes a left-eye image and a right-eye image.

[0086] The display total frame TF includes at least a first color frame R1, in which the first type of light is modulated by the liquid crystal grating 100 to obtain a first deflected light. In other words, in the first color frame R1, the luminous color of the light incident on the liquid crystal grating 100 is consistent, and the deflection direction of the light incident on the liquid crystal grating 100 is consistent. Therefore, for the first color frames in a plurality of display total frames TF, the deflection degree of the liquid crystal 30 should be the same. Exemplarily, the display total frame TF includes at least a first red frame, in which the liquid crystal grating 100 deflects the incident red light toward the left eye.

[0087] Due to the electrical bending phenomenon, if the voltages of different polarities achieve the same deflection direction for the liquid crystal 30, the amplitudes of the voltages of different polarities are different. That is, the average voltage value |V1| of the first voltage of the first polarity provided to the liquid crystal grating 100 is less than the amplitude |V2| of the second voltage of the second polarity. At this time, if only the DC balance of the first color frame R1 is considered, it is at least necessary to satisfy that at least in one first color frame R1, the working state of the liquid crystal grating 100 is the first mode, and in at least one first color frame R1, the working state of the liquid crystal grating 100 is the second mode. Exemplarily, for deflecting red light toward the left eye, when the working state of the liquid crystal grating 100 is the first mode, the average voltage value of the grating electrode group 10 is |+2.5|V; when the working state of the liquid crystal grating 100 is the second mode, the average voltage value of the grating electrode group 10 is |-3.5|V. In this way, in the first color frame of multiple display total frames TF, there are both the first voltage of the first polarity and the second voltage of the second polarity. Furthermore, the number N1 of the first modes is greater than the number N2 of the second modes, so that the DC imbalance caused by the excessive component of a voltage of a certain polarity in the first color frame R1 can be avoided, thereby affecting the display effect.

[0088] In another optional embodiment provided by the present invention, referring to Figure 7 As shown, Figure 7 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention. The working cycle T includes N total display frames TF; wherein N=N1+N2; a total display frame TF includes multiple subframes ( Figure 7 R1, G1, B1, R2, G2, B2 are used to represent subframes);

[0089] In a display total frame TF of the liquid crystal grating 100, in at least one subframe, the working state of the liquid crystal grating 100 is the first mode ( Figure 7In the figure, + represents the first mode), and in at least one subframe, the working state of the liquid crystal grating 100 is the second mode ( Figure 7 - is used to indicate the second mode).

[0090] One working cycle T of the liquid crystal grating 100 includes N total display frames TF, wherein the total display frames TF are used to provide a display picture. Specifically, one display picture includes a left-eye image and a right-eye image.

[0091] It should be noted that the three primary colors of optics refer to red, green and blue. That is to say, light rays with red, green and blue luminous colors can be mixed in different proportions to form a variety of colors, thereby forming a display screen.

[0092] Therefore, the multiple subframes included in a total display frame TF can be modulated to light of different colors, or modulate light at different angles. Exemplarily, the total display frame TF includes 6 subframes, namely, the first red frame R1, the first green frame G1, the first blue frame B1, the second red frame R2, the second green frame G2, and the second blue frame B2. Among them, in the first red frame R1, the liquid crystal grating 100 deflects the incident red light in the direction of the left eye. Similarly, in the first green frame G1 and the first blue frame B1, the liquid crystal grating 100 deflects the incident green light or blue light in the direction of the left eye. The red light, green light, and blue light deflected in the direction of the left eye by the liquid crystal grating 100 form a left eye image. In the second red frame R2, the liquid crystal grating 100 deflects the incident red light in the direction of the right eye. In the second green frame G2 and the second blue frame B2, the liquid crystal grating 100 deflects the incident green light or blue light in the direction of the right eye. The red light, the green light and the blue light deflected toward the right eye by the liquid crystal grating 100 form a right eye image.

[0093] It should be noted that, generally speaking, for light rays of different luminous colors, the amplitude of the voltage to achieve the same deflection direction is not exactly the same. Therefore, in any two subframes in a total display frame TF, regardless of whether the luminous colors of the light rays modulated by the liquid crystal grating 100 are the same, or whether the angles of the deflected light rays are the same, the average voltage values ​​of the voltages driving the two subframes are different.

[0094] Therefore, in the embodiment provided by the present invention, among the multiple subframes included in the display total frame TF, in at least one subframe, the working state of the liquid crystal grating 100 is the first mode, and in at least one subframe, the working state of the liquid crystal grating 100 is the second mode. In this way, in one display total frame TF, there is both a first voltage of the first polarity and a second voltage of the second polarity. And the number N1 of the first mode is greater than the number N2 of the second mode, which can avoid the DC imbalance caused by the excessive component of a voltage of a certain polarity in one display total frame TF, thereby affecting the display effect.

[0095] In another optional embodiment provided by the present invention, referring to Figure 8 and Fig. 9 As shown, Figure 8 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention, Fig. 9 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention. A total display frame TF includes M subframes ( Figure 8 and Fig. 9 R1, G1, B1, R2, G2, B2 are used to represent subframes), M is a positive integer;

[0096] The working state of the liquid crystal grating 100 is the first mode ( Figure 8 and Fig. 9 The number of subframes is M1, and the working state of the liquid crystal grating 100 is the second mode ( Figure 8 and Fig. 9 The number of subframes of the second mode (in which - is used to represent the second mode) is M2, where M1=M2.

[0097] A total display frame TF includes M subframes, and the M subframes are arranged in sequence. In the embodiment provided by the present invention, the number of subframes M1 in which the working state of the liquid crystal grating 100 is the first mode is equal to the number of subframes M2 in which the working state of the liquid crystal grating 100 is the second mode. That is, in a total display frame TF, the number of times the voltage of the first polarity is provided to the liquid crystal grating 100 is equal to the number of times the voltage of the second polarity is provided. Multiple first modes and multiple second modes in a total display frame TF can be as follows: Figure 8 As shown, they are arranged alternately in multiple subframes; they can also be arranged as shown Fig. 9 As shown, a plurality of first modes are arranged adjacent to each other, and a plurality of second modes are arranged adjacent to each other.

[0098] In the embodiment provided by the present invention, in one display total frame TF, the number of the first mode is equal to the number of the second mode. It is possible to adjust the DC balance in one display total frame TF so that voltages of different polarities appear in sequence or alternately, thereby avoiding DC imbalance caused by excessive component of a voltage of a certain polarity in one display total frame TF, thereby affecting the display effect.

[0099] In another optional embodiment provided by the present invention, referring to Fig.10 As shown, Fig.10 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention. A total display frame TF includes M subframes ( Fig.10 R1, G1, B1, R2, G2, B2 are used to represent subframes), M is a positive integer;

[0100] The working state of the liquid crystal grating 100 is the first mode ( Fig.10 The number of subframes is M1, and the working state of the liquid crystal grating 100 is the second mode ( Fig.10 The number of subframes of the second mode (in which - is used to represent the second mode) is M2, where M1>M2.

[0101] Since the liquid crystal grating 100 deflects incident light rays of different colors at different angles in different subframes of a display total frame TF, the deflection angles of the liquid crystal 30 are not completely the same when modulating light rays of different colors or at different angles. Exemplarily, when the liquid crystal grating 100 deflects incident red light rays, green light rays, and blue light rays toward the left eye, when deflecting the red light rays, the voltage provided to the liquid crystal grating 100 is greater than the voltage provided to the liquid crystal grating 100 when deflecting the green light rays or the blue light rays.

[0102] Therefore, in the same display total frame TF, the number of subframes M1 in which the working state of the liquid crystal grating 100 is the first mode is greater than the number of subframes M2 in which the working state of the liquid crystal grating 100 is the first mode. Among them, the subframe in which the working state of the liquid crystal grating 100 is the first mode can be a subframe or multiple subframes in which the average voltage value of the grating electrode group 10 is smaller; the subframe in which the working state of the liquid crystal grating 100 is the second mode can be a subframe or multiple subframes in which the average voltage value of the grating electrode group 10 is larger. In this way, it is possible to avoid DC imbalance caused by excessive component of a voltage of a certain polarity in a display total frame TF, which affects the display effect.

[0103] In a total display frame TF, the number of subframes in the first mode or the second mode should also be considered from the entire working cycle T of the liquid crystal grating 100. The number M1 of subframes in the first mode of the liquid crystal grating 100 is greater than the number M2 of subframes in the first mode of the liquid crystal grating 100, which can not only adjust the DC balance of a total display frame TF, but also adjust the DC balance of a working cycle T, further improving the display effect.

[0104] In another optional embodiment provided by the present invention, continue to refer to Figure 7The subframe includes a first subframe R1 and a second subframe G1, the working state of the liquid crystal grating 100 in the first subframe R1 is a first mode, and the working state of the liquid crystal grating 100 in the second subframe R2 is a second mode, wherein the first subframe R1 is used to modulate a first type of light, and the second subframe R2 is used to modulate a second type of light, and the colors of the first type of light and the second type of light are different.

[0105] The subframe includes a first subframe R1 and a second subframe G1. The first subframe R1 is used to modulate the first type of light, and the second subframe G1 is used to modulate the second type of light. The colors of the first type of light and the second type of light are different. Exemplarily, the first type of light is red light, and the second type of light is green light. At this time, in the first subframe R1, the voltage provided to the liquid crystal grating 100 should be adapted to the amplitude of the red light deflection, and in the second subframe G1, the voltage provided to the liquid crystal grating 100 should be adapted to the amplitude of the green light deflection.

[0106] In the first subframe R1, the working state of the liquid crystal grating 100 is the first mode, and in the second subframe G1, the working state of the liquid crystal grating 100 is the second mode. That is, in the subframes for modulating light of different colors, the working modes of the liquid crystal grating 100 are different.

[0107] In the embodiment provided by the present invention, in the subframes for modulating light of different colors, the working state of the liquid crystal grating 100 is the first mode at least in the first subframe R1, and the working state is the second mode at least in the second subframe G1. In this way, in the same display total frame TF, both the first voltage of the first polarity and the second voltage of the second polarity can be provided to the liquid crystal grating 100. In addition, the amplitude of the voltage required for the liquid crystal grating 100 to modulate light of different colors is different. Therefore, the embodiment provided by the present invention can adjust the number of working states of the subframes for modulating light of different colors in one display total frame TF, so that the DC of the liquid crystal grating 100 is balanced.

[0108] In another optional embodiment provided by the present invention, the first subframe R1 is used to modulate the first color light, and the second subframe G1 is used to modulate the second color light, wherein the wavelength of the first color light is smaller than the wavelength of the second color light.

[0109] In the first subframe R1 and the second subframe G1, the liquid crystal grating 100 modulates the first color light and the second color light respectively. The wavelength of the first color light is smaller than the wavelength of the second color light. Exemplarily, the first color light is green light, and its wavelength is 492nm~577nm; the second color light is red light, and its wavelength is 622nm~760nm. At this time, the wavelength of the first color light is smaller than the wavelength of the second color. For another example, the first color light is blue light, and its wavelength is 400nm~450nm; the second color light is green light, and its wavelength is 492nm~577nm. At this time, the wavelength of the first color light is also smaller than the wavelength of the second color.

[0110] When the liquid crystal grating 100 modulates light of different wavelengths (colors) and the deflection angles are the same, the deflection angles of the liquid crystal 30 in the liquid crystal grating 100 are different to form different prism structures. Therefore, for light of different wavelengths (colors), different voltages are provided to the liquid crystal grating 100. Therefore, the embodiment provided by the present invention can adjust the number of working states of the subframes in the liquid crystal grating 100 that modulate light of different wavelengths (colors), so that the DC of the liquid crystal grating 100 is balanced.

[0111] In another optional embodiment provided by the present invention, continue to refer to Figure 8 The subframe includes a third subframe B1 and a fourth subframe B2, the working state of the liquid crystal grating in the third subframe B1 is the first mode, and the working state of the liquid crystal grating 100 in the fourth subframe B2 is the second mode, wherein the third subframe B1 is used to modulate the third type of light, and the fourth subframe B2 is used to modulate the fourth type of light, and the third type of light and the fourth type of light have the same color and different deflection angles.

[0112] The subframe includes a third subframe B1 and a fourth subframe B2. The third subframe B1 is used to modulate the third type of light, and the fourth subframe B2 is used to modulate the fourth type of light. The third type of light and the fourth type of light have the same color, but different deflection angles. Exemplarily, the third type of light is blue light deflected toward the left eye, and the fourth type of light is blue light deflected toward the right eye. At this time, in the third subframe B1, the voltage provided to the liquid crystal grating 100 should be adapted to the amplitude that deflects the blue light toward the left eye, and in the fourth subframe B2, the voltage provided to the liquid crystal grating 100 should be adapted to the amplitude that deflects the blue light toward the right eye.

[0113] In the third subframe B1, the working state of the liquid crystal grating 100 is the first mode, and in the fourth subframe B2, the working state of the liquid crystal grating 100 is the second mode. That is, in the subframes where light of the same color is modulated at different deflection angles, the working modes of the liquid crystal grating 100 are different.

[0114] In the embodiment provided by the present invention, in the subframes for modulating light with different deflection directions, the working state of the liquid crystal grating 100 is the first mode at least in the third subframe B2, and the working state is the second mode at least in the fourth subframe B2. In this way, in the same display total frame TF, both the first voltage of the first polarity and the second voltage of the second polarity can be provided to the liquid crystal grating 100. In addition, the amplitude of the voltage required when the liquid crystal grating 100 modulates light with different deflection directions is different. Therefore, the embodiment provided by the present invention can adjust the number of working states of the subframes for light with different deflection directions in one display total frame TF, so that the DC of the liquid crystal grating 100 is balanced.

[0115] In another optional embodiment provided by the present invention, referring to Figure 3 and Fig.11 As shown, Fig.11 Another timing diagram of the liquid crystal grating provided by the embodiment of the present invention. The total display frame TF includes a first color frame R, a second color frame G and a third color frame B modulating light of different colors, wherein the first color frame R includes two subframes, the second color frame G includes two subframes, and the third color frame B includes two subframes.

[0116] In the embodiment provided by the present invention, the total display frame TF includes a first color frame R, a second color frame G, and a third color frame B. In the first color frame R, the second color frame G, and the third color frame B, the colors of the light modulated by the liquid crystal grating 100 are different. Exemplarily, in the first color frame R, the liquid crystal grating 100 modulates red light; in the second color frame G, the liquid crystal grating 100 modulates green light; in the third color frame B, the liquid crystal grating 100 modulates blue light.

[0117] The first color frame R, the second color frame G, and the third color frame B each include two subframes. In the two subframes in the same color frame, the liquid crystal grating 100 modulates the light of the same color in different deflection directions. Exemplarily, the first color frame R includes a first color subframe R1 and a second color subframe R2, and in the first color subframe R1, the liquid crystal grating 100 modulates the red light to be deflected in the left eye direction. In the second color subframe R2, the liquid crystal grating 100 modulates the red light to be deflected in the right eye direction. Similarly, the second color frame G includes a third color subframe G1 and a fourth color subframe G2, and the third color frame B includes a fifth color subframe B1 and a sixth color subframe B2. In the third color subframe G1, the liquid crystal grating 100 modulates the green light to be deflected in the left eye direction. In the fourth color subframe G2, the liquid crystal grating 100 modulates the green light to be deflected in the right eye direction. In the fifth color subframe B1, the liquid crystal grating 100 modulates the blue light to be deflected in the left eye direction. In the sixth color subframe B2, the liquid crystal grating 100 modulates the blue light to be deflected in the right eye direction. Among them, the red light, green light and blue light modulated in the first color subframe R1, the third color subframe G1 and the fifth color subframe B1 and deflected in the left eye direction constitute the left eye image. The red light, green light and blue light modulated in the second color subframe R2, the fourth color subframe G2 and the sixth color subframe B2 and deflected in the right eye direction constitute the right eye image.

[0118] In the embodiment provided by the present invention, a total display frame TF includes at least 6 sub-frames ( Fig.11 In the figure, R1, G1, B1, R2, G2, and B2 are used to represent subframes. In the six subframes, the color or deflection direction of the light modulated by the liquid crystal grating 100 is different. Lights of different colors or different deflection directions constitute the left eye image and the right eye image, realizing holographic display.

[0119] In another optional embodiment provided by the present invention, continue to refer to Fig.11 As shown, in the two subframes included in the first color frame R, the working states of the liquid crystal grating 100 are respectively the first mode and the second mode.

[0120] The first color frame R includes two subframes, that is, two subframes in which the liquid crystal grating 100 modulates the light of the same color in different deflection directions. The working states of the liquid crystal grating 100 are respectively a first mode and a second mode.

[0121] In the two subframes of the first color frame, the working states of the liquid crystal grating 100 are respectively the first mode and the second mode. It can be that when the modulated light is deflected toward the left eye, the working mode of the liquid crystal grating 100 is the first mode, and when the modulated light is deflected toward the right eye, the working mode of the liquid crystal grating 100 is the second mode. It can also be that when the modulated light is deflected toward the right eye, the working mode of the liquid crystal grating 100 is the first mode, and when the modulated light is deflected toward the left eye, the working mode of the liquid crystal grating 100 is the second mode.

[0122] In the embodiment provided by the present invention, in the first color frame R, both a first voltage of a first polarity and a second voltage of a second polarity are provided to the liquid crystal grating 100 , so that the direct current of the liquid crystal grating 100 can be close to balance.

[0123] In another optional embodiment provided by the present invention, the first polarity is positive polarity, and the second polarity is negative polarity.

[0124] In the embodiment provided by the present invention, the first polarity is positive polarity, and the second polarity is negative polarity. Therefore, in the process of adjusting the number of working states of the liquid crystal grating 100, the components of the voltage of the positive polarity and the components of the voltage of the negative polarity are made to be close to each other, so as to avoid the DC imbalance of the liquid crystal grating 100 caused by the excessive component of a voltage of a certain polarity, thereby affecting the display effect.

[0125] Based on the same inventive concept, the embodiment of the present invention also provides another liquid crystal grating. Figure 1 and Figure 3 As shown, another liquid crystal grating 100 provided by an embodiment of the present invention includes a plurality of grating electrode groups 10, and one grating electrode group 10 includes a plurality of grating electrodes 01;

[0126] The working state of the liquid crystal grating 100 includes a first mode and a second mode.

[0127] In the first mode, a first voltage of a first polarity is provided to the grating electrode 01 , and for one grating electrode group 10 , a maximum voltage value of the first voltage is |V1max|;

[0128] In the second mode, a second voltage of a second polarity is provided to the grating electrode 01, and for one grating electrode group 10, the maximum voltage value of the second voltage is |V2max|;

[0129] Wherein, the first polarity is different from the second polarity, and |V1max|<|V2max|;

[0130] In one working cycle T of the liquid crystal grating 100, the light is modulated by the liquid crystal grating 100 to obtain deflected light, and the liquid crystal grating 100 switches between a first mode and a second mode, the number of the first modes is N1, and the number of the second modes is N2;

[0131] Wherein, N1>N2, and N1 and N2 are positive integers.

[0132] In the liquid crystal grating 100 provided by the present invention, the maximum voltage value of the first voltage |V1max| and the maximum voltage value of the second voltage |V2max| are used to represent the magnitude of the voltage of the first polarity and the voltage of the second polarity. In order to make the liquid crystal grating 100 achieve DC balance during long-term use, it is necessary to determine the quantitative relationship between the first mode of providing the first voltage of the first polarity to the liquid crystal grating 100 and the second mode of providing the second voltage of the second polarity to the liquid crystal grating 100 according to the magnitude of the voltage of the first polarity and the voltage of the second polarity. Since |V1max|<|V2max|, the number of the first mode N1 is greater than the number of the second mode N2. The quantitative relationship between the first mode and the second mode is inversely correlated with the maximum value relationship between the first voltage in the first mode and the second voltage in the second mode. In this way, the voltage component of the first polarity and the voltage component of the second polarity can be close to balance, thereby improving the display effect.

[0133] Based on the same inventive concept, the present invention also provides a holographic display device, referring to Fig.12 As shown, Fig.12 A schematic diagram of the structure of a holographic display device provided in an embodiment of the present invention. The holographic display device 1000 includes the liquid crystal grating 100 in any of the above embodiments. The holographic display device 1000 also includes a field lens 200, a spatial light modulator 300 and a backlight source 400. The spatial light modulator 300, the field lens 200 and the liquid crystal grating 100 are sequentially arranged on one side of the light exit surface of the backlight source 400. In the same holographic display device 1000, the liquid crystal grating 100 may include one or more.

[0134] In summary, the liquid crystal grating and holographic display device provided by the present invention achieve at least the following beneficial effects:

[0135] In the embodiment provided by the present invention, the number of the first mode and the second mode is limited within a working cycle T of the liquid crystal grating. Specifically, for the first mode and the second mode with different polarities of the voltage provided to the liquid crystal grating, if the average voltage value |V1| of the first voltage provided to the grating electrode group in the first mode is less than the average voltage value |V2| of the second voltage provided to the grating electrode group in the second mode, then in a working cycle T of the liquid crystal grating, the number of the first mode N1 is greater than the number of the second mode N2, so that the components of the voltages of different polarities are close to the same within a working cycle T, thereby achieving DC balance. The embodiment provided by the present invention does not need to change the original physical structure or circuit structure of the liquid crystal grating, and can avoid the occurrence of afterimages and improve the display effect, which is simpler and more convenient.

[0136] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A liquid crystal grating, It is characterized in that comprising a plurality of grating electrode groups, wherein one of the grating electrode groups comprises a plurality of grating electrodes; The working state of the liquid crystal grating includes a first mode and a second mode, In the first mode, a first voltage of a first polarity is provided to the grating electrode, and for one grating electrode group, an average voltage value of the first voltage is |V1|; In the second mode, a second voltage of a second polarity is provided to the grating electrode, and for one grating electrode group, an average voltage value of the second voltage is |V2|; The first polarity is different from the second polarity, and |V1|<|V2|; In one working cycle of the liquid crystal grating, light is modulated by the liquid crystal grating to obtain deflected light, and the liquid crystal grating switches between the first mode and the second mode, the number of the first modes is N1, and the number of the second modes is N2; Wherein, N1>N2, and N1 and N2 are positive integers.

2. The liquid crystal grating according to claim 1, It is characterized in that |V1|, |V2|, N1, N2 satisfy: Wherein, m is the first correction coefficient, 0.8≤m≤1.

2.

3. The liquid crystal grating according to claim 2, It is characterized in that The first correction coefficient m=1.

4. The liquid crystal grating according to claim 1, It is characterized in that |V1|, |V2|, N1, N2 satisfy: Wherein, n is the second correction coefficient, n≤0.

5.

5. The liquid crystal grating according to claim 1, It is characterized in that Along the arrangement direction of the grating electrodes, the amplitudes of the potentials of the plurality of grating electrodes in the same grating electrode group increase sequentially; The average voltage of the grating electrode group is an arithmetic average of the amplitudes of the potentials of the plurality of grating electrodes included in the grating electrode group.

6. The liquid crystal grating according to claim 1, It is characterized in that The working state of the liquid crystal grating is that the first mode and the second mode are arranged alternately.

7. The liquid crystal grating according to claim 1, It is characterized in that The working state of the liquid crystal grating is that a plurality of the first modes are arranged adjacent to each other, and a plurality of the second modes are arranged adjacent to each other.

8. The liquid crystal grating according to claim 1, It is characterized in that The working cycle includes N total display frames; wherein N=N1+N2; the total display frame includes at least a first color frame; In the first color frame, the first type of light is modulated by the liquid crystal grating to obtain a first deflected light; In one working cycle of the liquid crystal grating, in at least one of the first color frames, the working state of the liquid crystal grating is the first mode, and in at least one of the first color frames, the working state of the liquid crystal grating is the second mode.

9. The liquid crystal grating according to claim 1, It is characterized in that The working cycle includes N total display frames; Wherein N=N1+N2; one total display frame includes a plurality of subframes; In a total display frame of the liquid crystal grating, in at least one of the subframes, the working state of the liquid crystal grating is the first mode, and in at least one of the subframes, the working state of the liquid crystal grating is the second mode.

10. The liquid crystal grating according to claim 9, It is characterized in that One of the total display frames includes M subframes, where M is a positive integer; The number of subframes when the working state of the liquid crystal grating is the first mode is M1, and the number of subframes when the working state of the liquid crystal grating is the second mode is M2, wherein M1=M2.

11. The liquid crystal grating according to claim 9, It is characterized in that One of the total display frames includes M subframes, where M is a positive integer; The number of subframes when the working state of the liquid crystal grating is the first mode is M1, and the number of subframes when the working state of the liquid crystal grating is the second mode is M2, wherein M1>M2.

12. The liquid crystal grating according to claim 9, It is characterized in that The subframe includes a first subframe and a second subframe, the working state of the liquid crystal grating in the first subframe is the first mode, and the working state of the liquid crystal grating in the second subframe is the second mode; wherein the first subframe is used to modulate a first type of light, and the second subframe is used to modulate a second type of light, and the colors of the first type of light and the second type of light are different.

13. The liquid crystal grating according to claim 12, It is characterized in that The first subframe is used to modulate a first color light, and the second subframe is used to modulate a second color light; wherein the wavelength of the first color light is smaller than the wavelength of the second color light.

14. The liquid crystal grating according to claim 9, It is characterized in that The subframes include a third subframe and a fourth subframe, the working state of the liquid crystal grating in the third subframe is the first mode, and the working state of the liquid crystal grating in the fourth subframe is the second mode; wherein the third subframe is used to modulate a third type of light, and the fourth subframe is used to modulate a fourth type of light, the third type of light and the fourth type of light have the same color and different deflection angles.

15. The liquid crystal grating according to claim 9, It is characterized in that The total display frame includes a first color frame, a second color frame and a third color frame that modulate light of different colors; wherein the first color frame includes two sub-frames, the second color frame includes two sub-frames, and the third color frame includes two sub-frames.

16. The liquid crystal grating according to claim 15, It is characterized in that In the two subframes included in the first color frame, the working states of the liquid crystal grating are respectively the first mode and the second mode.

17. The liquid crystal grating according to claim 1, It is characterized in that The first polarity is positive polarity, and the second polarity is negative polarity.

18. A liquid crystal grating, It is characterized in that comprising a plurality of grating electrode groups, wherein one of the grating electrode groups comprises a plurality of grating electrodes; The working state of the liquid crystal grating includes a first mode and a second mode, In the first mode, a first voltage of a first polarity is provided to the grating electrode, and for one grating electrode group, a maximum voltage value of the first voltage is |V1max|; In the second mode, a second voltage of a second polarity is provided to the grating electrodes, and for one grating electrode group, a maximum voltage value of the second voltage is |V2max|; Wherein, the first polarity is different from the second polarity, and |V1max|<|V2max|; In one working cycle of the liquid crystal grating, light is modulated by the liquid crystal grating to obtain deflected light, and the liquid crystal grating switches between the first mode and the second mode, the number of the first modes is N1, and the number of the second modes is N2; Wherein, N1>N2, and N1 and N2 are positive integers.

19. A holographic display device, It is characterized in that Comprising the liquid crystal grating as described in any one of claims 1-18.

Images