Liquid crystal lens assembly, liquid crystal lens display device and driving method

Abstract

The present invention provides a liquid crystal lens assembly, a liquid crystal lens display device, and a driving method. The liquid crystal lens assembly includes a liquid crystal wave plate, a first liquid crystal lens unit, a second liquid crystal lens unit, and a control system. The control system is configured to control the liquid crystal wave plate to switch between a first state and a second state. The control system controls a first driving voltage applied to the first liquid crystal lens unit and a second driving voltage applied to the second liquid crystal lens unit according to a target focal length of the liquid crystal lens assembly to achieve the target focal length. The zoom of the liquid crystal lens assembly depends only on the magnitude of the driving voltages of the first liquid crystal lens unit and the second liquid crystal lens unit, which helps reduce the zoom response time of the liquid crystal lens assembly. By setting the overdrive voltage, the response time of the liquid crystal lens assembly switching between different focal lengths remains consistent, which helps improve the display effect of the liquid crystal lens assembly.

Description

Technical Field

[0001] The present invention generally relates to the field of display technology, and in particular to a liquid crystal lens assembly, a liquid crystal lens display device, and a driving method. Background Art

[0002] With the continuous development of liquid crystal technology, liquid crystal materials are widely used in display technology, various optical devices, and other fields. Liquid crystal lenses are optical components that use the birefringence of liquid crystal molecules and their ability to shift their alignment in response to the electric field distribution to focus or diverge light beams. Liquid crystal lenses can achieve variable focal length by changing the alignment of liquid crystal molecules by varying the driving voltage, thereby achieving an effective optical zoom effect within a compact space.

[0003] Liquid crystal lens technology is widely used in three-dimensional stereoscopic display. The main reason is that it has high flexibility. It only needs to control the voltage distribution of the corresponding electrodes in the liquid crystal layer, and the refractive index distribution of the liquid crystal lens will change accordingly, thereby controlling the distribution of the pixel output light and realizing free stereoscopic display and free switching between 2D / 3D.

[0004] In order to achieve dynamic and smooth switching of images, the stereoscopic display device needs to have a dynamic zoom display function, thereby realizing fast and free switching between 2D / 3D. In the existing technology, this function is mostly achieved by reducing the thickness of the liquid crystal lens box, improving the characteristics of the liquid crystal material, increasing the driving voltage, or setting a special electrode structure to form a horizontal electric field to accelerate the liquid crystal molecules to return to their initial orientation position. For example, a method of setting a special electrode structure to form a horizontal electric field to achieve a faster response speed. However, the electrode structure design of this type of lens is relatively complex, and most liquid crystal lenses are still limited by the influence of power-off response time. On the one hand, this limits the application of dynamic zoom. On the other hand, the response speed of switching between different focal lengths varies, which seriously affects the display smoothness of the 2D / 3D switching process and affects the visual experience.

[0005] The contents of the background technology section are merely the technologies known to the inventors and do not necessarily represent the existing technologies in this field. Summary of the Invention

[0006] In view of one or more deficiencies in the prior art, the present invention provides a liquid crystal lens unit, a liquid crystal lens display device, and a driving method.

[0007] The present invention provides a liquid crystal lens assembly, comprising:

[0008] A liquid crystal wave plate having a first state and a second state, wherein in the first state, the liquid crystal wave plate maintains the polarization direction of the first linearly polarized light passing therethrough unchanged; and in the second state, the liquid crystal wave plate rotates the polarization direction of the first linearly polarized light passing therethrough by a certain angle and emits a second linearly polarized light;

[0009] a first liquid crystal lens unit located downstream of the optical path of the liquid crystal wave plate, the focal length of which is adjustable according to a first driving voltage applied to the first liquid crystal lens unit;

[0010] a second liquid crystal lens unit located downstream of the optical path of the first liquid crystal lens unit, the focal length of which is adjustable according to a second driving voltage applied to the second liquid crystal lens unit; and

[0011] a control system electrically connected to the liquid crystal wave plate, the first liquid crystal lens unit, and the second liquid crystal lens unit, and configured to control the liquid crystal wave plate to switch between a first state and a second state, and to control a first driving voltage applied to the first liquid crystal lens unit and a second driving voltage applied to the second liquid crystal lens unit according to a target focal length of the liquid crystal lens assembly to obtain the target focal length.

[0012] According to one aspect of the present invention, the control system comprises:

[0013] a control unit configured to determine the first driving voltage and the second driving voltage according to a target focal length of the liquid crystal lens assembly;

[0014] A driving unit is connected to the control unit, the first liquid crystal lens unit, and the second liquid crystal lens unit, respectively, and is configured to apply the first driving voltage and the second driving voltage to the first liquid crystal lens unit and the second liquid crystal lens unit, respectively.

[0015] According to one aspect of the present invention, the first liquid crystal lens unit includes one or more first liquid crystal lenses, and the second liquid crystal lens unit includes one or more second liquid crystal lenses, wherein the first liquid crystal lenses are rubbed and aligned along a first direction, and the second liquid crystal lenses are rubbed and aligned along a second direction, the first direction is the same as the polarization direction of the first linearly polarized light, and the second direction is the same as the polarization direction of the second linearly polarized light.

[0016] According to one aspect of the present invention, the first direction and the second direction have an angle of 70-110°.

[0017] According to one aspect of the present invention, the control system is configured to: select one of the first liquid crystal lens unit and the second liquid crystal lens unit, switch the liquid crystal wave plate to or maintain it in the first state or the second state, and obtain the target focal length by driving the selected one of the first liquid crystal lens unit and the second liquid crystal lens unit.

[0018] According to one aspect of the present invention, the apparatus further includes a tracking unit configured to determine the target focal length by eye tracking or gaze tracking.

[0019] According to one aspect of the present invention, a storage unit is further included, wherein the storage unit stores the relationship between the focal length of the first liquid crystal lens unit and the first driving voltage, and the relationship between the focal length of the second liquid crystal lens unit and the second driving voltage, and the storage unit further stores information of the currently selected one of the first liquid crystal lens unit and the second liquid crystal lens unit.

[0020] According to one aspect of the present invention, the control system is configured to: when the first liquid crystal lens unit is selected from the first liquid crystal lens unit and the second liquid crystal lens unit, switch the liquid crystal wave plate to the first state; when the second liquid crystal lens unit is selected from the first liquid crystal lens unit and the second liquid crystal lens unit, switch the liquid crystal wave plate to the second state.

[0021] According to one aspect of the present invention, the control system is configured to:

[0022] When the target focal length of the liquid crystal lens assembly is greater than the current focal length, increasing the driving voltage of the currently selected one of the first liquid crystal lens unit and the second liquid crystal lens unit to obtain the target focal length;

[0023] When the target focal length of the liquid crystal lens assembly is less than the current focal length, the liquid crystal wave plate is switched between the first state and the second state, the driving voltage of the currently selected one is reset to zero, and another one is selected and the driving voltage of the other one is increased to obtain the target focal length.

[0024] According to one aspect of the present invention, the control system is configured to:

[0025] When the target focal length of the liquid crystal lens assembly is different from the current focal length, determining a response time for driving the selected one of the first liquid crystal lens unit and the second liquid crystal lens unit to the target focal length;

[0026] Determining the relationship between the response time and a preset time;

[0027] When the response time is less than the preset time, driving the selected one to obtain the target focal length;

[0028] If the response time is greater than the preset time, the liquid crystal wave plate is switched between the first state and the second state, the driving voltage of the currently selected one is reset to zero, another one is selected and the driving voltage of the other one is increased to obtain the target focal length.

[0029] According to one aspect of the present invention, the control system is configured to calculate or read the pre-stored response time in real time.

[0030] According to one aspect of the present invention, the control system is configured to drive the first liquid crystal lens unit and the second liquid crystal lens unit in an "overvoltage-stable" manner.

[0031] The present invention also provides a liquid crystal lens display device, comprising:

[0032] A display module, configured to emit image light, wherein the image light is first linearly polarized light;

[0033] The liquid crystal lens assembly according to any one of claims 1 to 12, wherein the liquid crystal lens assembly is arranged downstream of the optical path of the display module to receive and project the first linearly polarized light.

[0034] The present invention also provides a method for driving a liquid crystal lens assembly, wherein the liquid crystal lens assembly includes a liquid crystal wave plate, a first liquid crystal lens unit, and a second liquid crystal lens unit, and the driving method includes:

[0035] driving the first liquid crystal lens unit to a preset focal length with a preset voltage, switching the liquid crystal wave plate to a first state, or driving the second liquid crystal lens unit to a preset focal length with a preset voltage, switching the liquid crystal wave plate to a second state;

[0036] determining a target focal length of the liquid crystal lens assembly;

[0037] Select one of the first liquid crystal lens unit and the second liquid crystal lens unit, switch the liquid crystal wave plate to or maintain it in the first state or the second state, obtain a driving voltage corresponding to the target focal length for the selected one, and drive the selected one with the driving voltage.

[0038] According to one aspect of the present invention, the method further includes: determining the target focal length by eye tracking or line of sight tracking.

[0039] According to one aspect of the present invention, information on the relationship between the focal length and the driving voltage of the first liquid crystal lens unit, the relationship between the focal length and the driving voltage of the second liquid crystal lens unit, and the currently selected one is stored in a storage unit;

[0040] The step of obtaining the driving voltage corresponding to the target focal length includes: obtaining the driving voltage corresponding to the target focal length by querying the storage unit.

[0041] According to one aspect of the present invention, when the first liquid crystal lens unit is selected from the first liquid crystal lens unit and the second liquid crystal lens unit, the liquid crystal wave plate is switched to the first state; when the second liquid crystal lens unit is selected from the first liquid crystal lens unit and the second liquid crystal lens unit, the liquid crystal wave plate is switched to the second state.

[0042] According to one aspect of the present invention, the liquid crystal lens assembly is configured to receive first linearly polarized light, the first liquid crystal lens unit includes one or more first liquid crystal lenses, and the second liquid crystal lens unit includes one or more second liquid crystal lenses, wherein the first liquid crystal lenses are rubbed and aligned along a first direction, and the second liquid crystal lenses are rubbed and aligned along a second direction, and the first direction is the same as the polarization direction of the first linearly polarized light. The driving method further includes: when the second liquid crystal lens is selected, before the light enters the first liquid crystal lens unit, rotating the polarization direction of the first linearly polarized light to the second direction by the liquid crystal wave plate.

[0043] According to one aspect of the present invention, the step of selecting one of the first liquid crystal lens unit and the second liquid crystal lens unit to switch the liquid crystal wave plate to or maintain the liquid crystal wave plate in the first state or the second state comprises:

[0044] When the target focal length of the liquid crystal lens assembly is greater than the current focal length, maintaining the currently selected one and maintaining the liquid crystal wave plate in the first state or the second state;

[0045] When the target focal length of the liquid crystal lens assembly is smaller than the current focal length, the driving voltage of the currently selected one is reset to zero, another one is selected, and the liquid crystal wave plate is switched between the first state and the second state.

[0046] According to one aspect of the present invention, the step of selecting one of the first liquid crystal lens unit and the second liquid crystal lens unit to switch the liquid crystal wave plate to or maintain the liquid crystal wave plate in the first state or the second state comprises:

[0047] When the target focal length of the liquid crystal lens assembly is different from the current focal length, determining a response time for driving the selected one of the first liquid crystal lens unit and the second liquid crystal lens unit to the target focal length;

[0048] Determining the relationship between the response time and a preset time;

[0049] When the response time is less than the preset time, keeping the currently selected one, and keeping the liquid crystal wave plate in the first state or the second state;

[0050] If the response time is greater than the preset time, the driving voltage of the currently selected one is reset to zero, another one is selected, and the liquid crystal wave plate is switched between the first state and the second state.

[0051] According to one aspect of the present invention, the step of driving the selected one with the driving voltage comprises:

[0052] The selected one is driven in an "overvoltage-stable" manner.

[0053] Compared to existing technologies, embodiments of the present invention provide a liquid crystal lens assembly, a liquid crystal lens display device, and a driving method. The zoom of the liquid crystal lens assembly depends solely on the driving voltage of the first and second liquid crystal lens units, which helps reduce the zoom response time of the liquid crystal lens assembly. By adjusting the overdrive voltage, the response time of the liquid crystal lens assembly switching between different focal lengths remains consistent, which helps improve the display quality of the liquid crystal lens assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0055] Figure 1 A schematic diagram of a liquid crystal lens assembly according to an embodiment of the present invention is shown;

[0056] Figure 2 A specific method for controlling the focal length of a liquid crystal lens assembly according to a control system of a preferred embodiment of the present invention is shown;

[0057] Figure 3 A specific method for controlling a liquid crystal lens assembly by a control system according to another preferred embodiment of the present invention is shown;

[0058] Figure 4 A schematic diagram of a liquid crystal lens display device according to an embodiment of the present invention is shown;

[0059] like Figure 5a Shown Figure 4 A partial structural diagram of a liquid crystal lens display device 200; Figure 5b shows the state of the first liquid crystal lens unit when it is in operation; Figure 5c The state in which the second liquid crystal lens unit is in operation is shown.

[0060] Figure 6 A flow chart of a method for driving a liquid crystal lens assembly according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0061] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0062] In the description of the present invention, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," "clockwise," "counterclockwise," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for the purpose of facilitating the description of the present invention and simplifying the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of the aforementioned features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0063] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, removable, or integral connections; mechanical, electrical, or intercommunication connections; direct or indirect connections through an intermediary; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0064] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may also include the first and second features not being in direct contact but being in contact via another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or diagonally above the second feature, or may simply mean that the first feature is at a higher level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or diagonally above the second feature, or may simply mean that the first feature is at a lower level than the second feature.

[0065] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0066] The following describes embodiments of the present invention in conjunction with the accompanying drawings. It should be understood that the embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0067] Figure 1 A schematic diagram of a liquid crystal lens assembly 100 according to an embodiment of the present invention is shown below. Figure 1 Provide a detailed description.

[0068] like Figure 1As shown, the liquid crystal lens assembly 100 includes a liquid crystal wave plate 110, a first liquid crystal lens unit 120, a second liquid crystal lens unit 130, and a control system 140, which are arranged in sequence. The liquid crystal wave plate 110 has a first state and a second state. In the first state, the liquid crystal wave plate 110 maintains the polarization direction of the first linearly polarized light passing through it unchanged; in the second state, the liquid crystal wave plate 110 rotates the polarization direction of the first linearly polarized light passing through it by a certain angle and emits a second linearly polarized light. The first state can be, for example, a powered-on (on) state, and the second state can be, for example, a powered-off (off) state. By controlling the power on and off of the liquid crystal wave plate 110, the liquid crystal wave plate 110 can be switched between the first state and the second state, thereby controlling whether the polarization direction of the first linearly polarized light passing through it is modulated. In other embodiments, the first state can also be a powered-off (off) state, and the second state can also be a powered-on (on) state. The first liquid crystal lens unit 120 is disposed downstream of the optical path of the liquid crystal wave plate 110. The first liquid crystal lens unit 120 can focus first linearly polarized light. The focal length of the first liquid crystal lens unit 120 can be adjusted based on a first driving voltage applied to the first liquid crystal lens unit 120. When the first liquid crystal lens unit 120 is powered off or the first driving voltage is zero, the focal length of the first liquid crystal lens unit 120 is infinite, meaning that light (particularly the first linearly polarized light) is not focused. The second liquid crystal lens unit 130 is disposed downstream of the optical path of the first liquid crystal lens unit 120. The second liquid crystal lens unit 130 can focus second linearly polarized light. The focal length of the second liquid crystal lens unit 130 can be adjusted based on a second driving voltage applied to the second liquid crystal lens unit 130. When the second liquid crystal lens unit 130 is powered off or the second driving voltage is zero, the focal length of the second liquid crystal lens unit 130 is infinite, meaning that light (particularly the second linearly polarized light) is not focused. In other embodiments, the first liquid crystal lens unit 120 may be used to focus the second linearly polarized light, and the second liquid crystal lens unit 130 may be used to focus the first linearly polarized light.

[0069] When projecting a first linearly polarized light onto the liquid crystal lens assembly 100, if the liquid crystal wave plate 110 is in the first state, the liquid crystal wave plate 110 maintains the polarization direction of the first linearly polarized light passing through it unchanged. The first liquid crystal lens unit 120 converges (focuses) the first linearly polarized light, while the second liquid crystal lens unit 130 does not converge the first linearly polarized light. In this case, the focal length of the liquid crystal lens assembly 100 is determined by the first liquid crystal lens unit 120 (the focal length of the liquid crystal lens assembly 100 is the focal length of the first liquid crystal lens unit 120). If the liquid crystal wave plate 110 is in the second state, the liquid crystal wave plate 110 rotates the polarization direction of the first linearly polarized light passing through it by a certain angle and emits a second linearly polarized light. The first liquid crystal lens unit 120 does not converge the second linearly polarized light, while the second liquid crystal lens unit 130 converges the second linearly polarized light. In this case, the focal length of the liquid crystal lens assembly 100 is determined by the second liquid crystal lens unit 130 (the focal length of the liquid crystal lens assembly 100 is the focal length of the second liquid crystal lens unit 130).

[0070] like Figure 1 As shown, the control system 140 is electrically connected to the liquid crystal wave plate 110, the first liquid crystal lens unit 120, and the second liquid crystal lens unit 130 respectively; the control system 140 is configured to control the liquid crystal wave plate 110 to switch between a first state and a second state, and can control the first driving voltage applied to the first liquid crystal lens unit 120 and the second driving voltage applied to the second liquid crystal lens unit 130 according to the target focal length of the liquid crystal lens assembly 100 to obtain the target focal length.

[0071] Response time is a key technical parameter of liquid crystal devices. For liquid crystal lenses, response time refers to the time required for the liquid crystal lens to change from one relatively stable state to another during the switching of the driving voltage. The response time of a liquid crystal lens generally consists of two parts: the power-on response time and the power-off response time. Due to the capacitance between the liquid crystal molecules in the liquid crystal lens and the rotational viscosity of the liquid crystal molecules, the response time for the liquid crystal molecules to return to their initial state after the electric field is removed is much longer than the response time under electric field control. In other words, when the device is fixed, the power-on response time is mainly controlled by the driving voltage, while the power-off response time is mainly limited by the characteristics of the liquid crystal material. Therefore, the power-off response time is usually much longer than the power-on response time. In other words, the response time of the liquid crystal lens is mainly determined by the power-off response time. In the present invention, by controlling the liquid crystal wave plate 110 to switch between the first state and the second state and the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 to operate alternately, the zoom of the liquid crystal lens assembly 100 depends only on the magnitude of the driving voltage of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130, which helps to reduce the zoom response time of the liquid crystal lens assembly 100.

[0072] According to one embodiment of the present invention, Figure 1 As shown, the control system 140 is configured to drive the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 in an "overvoltage-stabilization" mode. Specifically, the "overvoltage-stabilization" mode for driving the first liquid crystal lens unit 120 is used as an example for illustration. After determining a target focal length, for example, the target focal length is provided by the first liquid crystal lens unit 120. A stabilization voltage corresponding to the target focal length can be determined based on the target focal length. That is, when the stabilization voltage is applied to the first liquid crystal lens unit 120, the first liquid crystal lens unit 120 will ultimately provide the target focal length. After determining the stabilization voltage, the first liquid crystal lens unit 120 is first rapidly driven to the target focal length using an overdrive voltage (higher than the stabilization voltage), and then driven using the stabilization voltage to stabilize the focal length of the first liquid crystal lens unit 120 at the target focal length. The stabilization voltage is used to maintain the focal length of the first liquid crystal lens unit 120 at the target focal length. The overdrive voltage, which is higher than the stabilization voltage, is used to accelerate the change in the alignment of the liquid crystal molecules in the first liquid crystal lens unit 120, allowing the first liquid crystal lens unit 120 to quickly zoom to the target focal length. Driving the first and second liquid crystal lens units 120 and 130 in this "overvoltage-stabilization" manner helps shorten the zoom response time of the liquid crystal lens assembly 100. Furthermore, by adjusting the overdrive voltage, the response time of the liquid crystal lens assembly 100 switching between different focal lengths can be kept consistent, for example, within 100ms or even tens of milliseconds, thereby improving the display quality of the liquid crystal lens assembly 100.

[0073] According to one embodiment of the present invention, Figure 1 As shown, the first liquid crystal lens unit 120 may include one or more first liquid crystal lenses, the first liquid crystal lenses are rubbed and oriented along a first direction, the first direction being the same as the polarization direction of the first linear polarized light; since the first liquid crystal lenses are rubbed and oriented along the first direction, the first liquid crystal lenses will only converge the first linear polarized light having the same polarization direction as the first direction, but will not converge the second linear polarized light. The second liquid crystal lens unit 130 may include one or more second liquid crystal lenses, the second liquid crystal lenses are rubbed and oriented along a second direction, the second direction being the same as the polarization direction of the second linear polarized light; since the second liquid crystal lenses are rubbed and oriented along the second direction, the second liquid crystal lenses will only converge the second linear polarized light having the same polarization direction as the second direction, but will not converge the second linear polarized light. Among them, the first liquid crystal lens, the second liquid crystal lens and the liquid crystal wave plate 110 can all be made of positive liquid crystal material, and the first liquid crystal lens and the second liquid crystal lens can be a refractive index gradient lens (microlens array) or a Fresnel liquid crystal lens.

[0074] According to one embodiment of the present invention, an angle α is formed between the first direction and the second direction. The angle α ranges from 70° to 110°. In this embodiment, α = 90° is used as an example. In this case, the polarization directions of the incident light suitable for the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 are orthogonal, so that the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 can respectively achieve a better converging effect on incident light at different angles.

[0075] According to one embodiment of the present invention, Figure 1 As shown, the control system 140 may include a control unit 142 and a driving unit 141, wherein the control unit 142 is configured to determine a first driving voltage and a second driving voltage based on a target focal length of the liquid crystal lens assembly 100. The driving unit 141 is connected to the control unit 142, the first liquid crystal lens unit 120, and the second liquid crystal lens unit 130, respectively. The driving unit 141 is configured to apply the first driving voltage and the second driving voltage to the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130, respectively, based on instructions from the control unit 142. In addition, the control unit 142 is configured to determine whether to switch the liquid crystal wave plate 110 to or maintain it in the first state or the second state based on the target focal length of the liquid crystal lens assembly 100, and the driving unit 141 is configured to power on or off the liquid crystal wave plate 110 to switch it to or maintain it in the first state or the second state.

[0076] According to one embodiment of the present invention, Figure 1 As shown, the liquid crystal lens assembly 100 may further include a tracking unit 150, which is electrically connected to the control unit 142. The tracking unit 150 is configured to determine the target focal length through eye tracking or implementation tracking. The tracking unit 150 can quickly and accurately obtain the target focal length of the liquid crystal lens assembly 100 for zooming, and feed the target focal length back to the control unit 142, so that the control unit 142 can determine the first driving voltage and the second driving voltage in real time based on the target focal length obtained by the tracking unit 150, thereby improving the smoothness and accuracy of the zooming of the liquid crystal lens assembly 100.

[0077] According to one embodiment of the present invention, Figure 1As shown, the control system 140 can be configured to select one of the first liquid crystal lens cell 120 and the second liquid crystal lens cell 130, switch the liquid crystal wave plate 110 to or maintain it in the first state or the second state, and obtain the target focal length by driving the selected one of the first liquid crystal lens cell 120 and the second liquid crystal lens cell 130. When the first liquid crystal lens cell 120 is selected from the first liquid crystal lens cell 120 and the second liquid crystal lens cell 130, the liquid crystal wave plate 110 is switched to the first state; when the second liquid crystal lens cell 130 is selected from the first liquid crystal lens cell 120 and the second liquid crystal lens cell 130, the liquid crystal wave plate 110 is switched to the second state.

[0078] Specifically, in this embodiment, when the target focal length of the liquid crystal lens assembly 100 is greater than the current focal length, the control system 140 increases the driving voltage of the currently selected one of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 to achieve the target focal length. When the target focal length of the liquid crystal lens assembly 100 is less than the current focal length, the control system 140 switches the liquid crystal wave plate 110 between the first state and the second state, resets the driving voltage of the currently selected one of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 to zero, selects the other of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130, and increases the driving voltage of the other one to achieve the target focal length. Taking the first liquid crystal lens unit 120 as an example, resetting the voltage of the first liquid crystal lens unit 120 to zero means applying a zero voltage to both sides of the electrode plates of the first liquid crystal lens in the first liquid crystal lens unit 120 (or de-energizing the first liquid crystal lens). At this point, the voltage across the electrode plates decreases until the liquid crystal molecules return to their initial state (at which point the focal length of the first liquid crystal lens unit 120 is infinite). In this embodiment, the zoom of the liquid crystal lens assembly 100 depends solely on the state of the liquid crystal glass 110 and the magnitude of the driving voltage of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130. By driving the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 in an "overvoltage-stable" manner, the zoom response time of the liquid crystal lens assembly 100 can be greatly shortened. The overdrive voltage can also be set to maintain a consistent response time when the liquid crystal lens assembly 100 switches between different focal lengths, thereby improving the display quality of the liquid crystal lens assembly 100. Figure 2 The specific method of controlling the liquid crystal lens assembly 100 by the control system 140 according to a preferred embodiment of the present invention is shown below. Figure 2 Detailed description.

[0079] like Figure 2As shown, in step S101, the liquid crystal lens assembly 100 is powered on and initialized. One of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 is selected and driven to a preset initial focal length f0 (also referred to as the current focal length). The initial focal length f0 can be greater than or equal to zero. Furthermore, the serial number of the selected liquid crystal lens unit can be stored.

[0080] In step S102, the target focal length f1 is determined. Figure 1 The tracking unit 150 shown determines the target focal length f1 in real time to satisfy the user's optimal viewing experience.

[0081] In step S103, it is determined whether the target focal length f1 is equal to the current focal length f0. If they are equal, there is no need to adjust the drive voltage, and the process returns to step S102 to continuously monitor the target focal length f1. If they are not equal, indicating that there is a discrepancy between the target focal length f1 and the current focal length f0, the process proceeds to step S104.

[0082] In step S104, it is determined whether the target focal length f1 is greater than the current focal length f0. If the target focal length f1 is not greater than the current focal length f0, the process proceeds to step S105; otherwise, the process proceeds to step S107.

[0083] In step S105, since the target focal length f1 is less than the current focal length f0, according to the present invention, another liquid crystal lens unit is switched to use. That is, the driving voltage of the currently selected liquid crystal lens unit is reset to zero, and the driving voltage of the other liquid crystal lens unit is switched to f1. In this way, the response speed of the liquid crystal lens assembly 100 can be improved. Preferably, when the liquid crystal lens unit is switched, the state of the liquid crystal wave plate is correspondingly switched. For example, when the first liquid crystal lens unit 120 is selected from the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130, the liquid crystal wave plate 110 is switched to the first state; when the second liquid crystal lens unit 130 is selected from the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130, the liquid crystal wave plate 110 is switched to the second state.

[0084] In step S106 , the current focal length f0 of the liquid crystal lens assembly 100 is set to f1 , and then the process returns to step S102 to continue detecting the target focal length f1 .

[0085] In step S107, since the target focal length f1 is greater than the current focal length f0, there is no need to switch the liquid crystal lens unit. The currently selected liquid crystal lens unit can be directly driven to the target focal length f1, while the driving voltage of the other unselected liquid crystal lens unit remains at zero. The process then proceeds to step S108, where the current focal length f0 of the liquid crystal lens assembly 100 is set to f1. The process then returns to step S102 to continue detecting the target focal length f1.

[0086] In another embodiment, when the target focal length of the liquid crystal lens assembly 100 differs from the current focal length, the control system 140 determines the response time required to drive the currently selected one of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 to the target focal length and determines the relationship between the response time and a preset time. The control system 140 may read a pre-stored response time. In other embodiments, the control system 140 may calculate the response time in real time. Directly reading the pre-stored response time by the control system 140 can reduce the computational complexity of the control system 140 and improve the zoom speed of the liquid crystal lens assembly 100. When the response time is less than the preset time, the currently selected one of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 is driven to achieve the target focal length. When the response time is greater than the preset time, the liquid crystal wave plate 110 is switched between the first state and the second state, the driving voltage of the currently selected one of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 is reset to zero, and the other one of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 is selected and the driving voltage of the other one is increased to achieve the target focal length. In this embodiment, by determining the relationship between the response time and the preset time, a selection is made between the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130. This ensures that the response time of the liquid crystal lens assembly 100 is always no greater than the response time set by the system (the preset time), thereby making the focus switching of the liquid crystal lens assembly 100 smoother and the display effect better.

[0087] Figure 3 The specific method of controlling the liquid crystal lens assembly 100 by the control system 140 according to another preferred embodiment of the present invention is shown below. Figure 3 Detailed description.

[0088] like Figure 3 As shown, in step S201, the liquid crystal lens assembly 100 is powered on and initialized. One of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 is selected and driven to a preset initial focal length f0 (also referred to as the current focal length). The initial focal length f0 can be greater than or equal to zero. Furthermore, the serial number of the selected liquid crystal lens unit can be stored for subsequent query.

[0089] In step S202, the target focal length f1 is determined. Figure 1 The tracking unit 150 shown determines the target focal length f1 in real time to satisfy the user's optimal viewing experience.

[0090] In step S203, it is determined whether the target focal length f1 is equal to the current focal length f0. If they are equal, there is no need to adjust the drive voltage, and the process returns to step S202 to continuously monitor the target focal length f1. If they are not equal, indicating that there is a discrepancy between the target focal length f1 and the current focal length f0, the process proceeds to step S204.

[0091] In step S204, it is determined whether the focal length switching time of the currently selected liquid crystal lens unit from the current focal length f0 to the target focal length f1 is greater than a set value. If the focal length switching time is not greater than the set value, the process proceeds to step S207, otherwise the process proceeds to step S205.

[0092] In step S205, because the focal length switching time is greater than the set value, according to the present invention, another liquid crystal lens unit is switched to use. That is, the driving voltage of the currently selected liquid crystal lens unit is reset to zero, and the driving voltage of the other liquid crystal lens unit is switched to f1. In this way, the response speed of the liquid crystal lens assembly 100 can be improved. Preferably, when the liquid crystal lens unit is switched, the state of the liquid crystal wave plate is correspondingly switched. For example, when the first liquid crystal lens unit 120 is selected from the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130, the liquid crystal wave plate 110 is switched to the first state; when the second liquid crystal lens unit 130 is selected from the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130, the liquid crystal wave plate 110 is switched to the second state.

[0093] In step S206 , the current focal length f0 of the liquid crystal lens assembly 100 is set to f1 , and then the process returns to step S202 to continue detecting the target focal length f1 .

[0094] In step S207, since the focal length switching time is less than the set value, there is no need to switch the liquid crystal lens unit. The currently selected liquid crystal lens unit is directly driven to the target focal length f1, and the driving voltage of the other unselected liquid crystal lens unit is kept at zero. Then, the process proceeds to step S208, where the current focal length f0 of the liquid crystal lens assembly 100 is set to f1, and the process returns to step S202 to continue detecting the target focal length f1.

[0095] According to one embodiment of the present invention, the liquid crystal lens assembly 100 may further include a storage unit 160, which is electrically connected to the control system 140. The storage unit 160 may store the relationship between the focal length of the first liquid crystal lens unit 120 and the first driving voltage, and the relationship between the focal length of the second liquid crystal lens unit 130 and the second driving voltage. After obtaining the target focal length of the liquid crystal lens assembly 100, the control system 140, particularly the control unit 142, may determine the values ​​of the first driving voltage and the second driving voltage by reading the relationship between the focal length and the driving voltage pre-stored in the storage unit 160. The storage unit 160 may also store information about which of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 is currently selected. By reading this information, the control system 140 can determine which of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 is currently selected. In another embodiment of the present invention, the storage unit 160 may further store a response time for driving the first liquid crystal lens unit 120 between different focal lengths and a response time for driving the second liquid crystal lens unit 130 between different focal lengths. The control system 140 may obtain the response time for driving the currently selected one of the first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 to the target focal length, i.e., the focal length switching time, by reading the storage unit 160.

[0096] Figure 4 A schematic diagram of a liquid crystal lens display device 200 according to an embodiment of the present invention is shown below. Figure 4 Provide a detailed description.

[0097] like Figure 4 As shown, the liquid crystal lens display device 200 includes a display module 210 and the liquid crystal lens assembly 100 described above. The display module 210 is configured to emit image light, which is first linearly polarized light. The liquid crystal lens assembly 100 is positioned downstream of the display module's optical path to receive and project the image light (first linearly polarized light). The display module 210 can be a display screen. When the light emitted from the display module is non-linearly polarized light, a polarizer or wave plate can be positioned on the light-emitting side of the display module to convert the light emitted from the display module into linearly polarized light.

[0098] like Figure 5a Shown Figure 4A partial structural diagram of a liquid crystal lens display device 200 is shown, which primarily illustrates the display module 210, liquid crystal wave plate 110, first liquid crystal lens unit 120, and second liquid crystal lens unit 130. The driving unit 141, control unit 142, storage unit 160, and tracking unit 150 are not shown. The output light from the display module 50 is linearly polarized light. When the output light from the display module 50 is non-linearly polarized light, a polarizer or wave plate can be provided on the light-exiting side to convert it into linearly polarized light. Assume that the polarization direction of the linearly polarized light is the x-axis. The rubbing direction of the first liquid crystal lens unit 120 is in the first direction, assumed here to be the x-axis direction. The rubbing direction of the second liquid crystal lens unit 130 is different from the first direction, assumed here to be the y-direction. The first direction and the second direction have a large angle α, ranging from 70° to 110°, with α preferably being 90°. In this case, the polarization directions of the incident light from the first and second liquid crystal lens units are orthogonal, respectively providing a good convergence effect on incident light at different angles. The first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 are stacked in the thickness direction (z-direction). The electrode structure of the first liquid crystal lens unit can be different from that of the second liquid crystal lens unit. The liquid crystal wave plate 110 has two states: an energized state in which the polarization direction of incident light is unchanged, and an energized state in which the polarization direction of incident polarized light is rotated by an angle α. Both the liquid crystal wave plate 110 and the liquid crystal lens units 120 / 130 use positive liquid crystal material. The first liquid crystal lens unit 120 and the second liquid crystal lens unit 130 can be gradient index lenses (microlens arrays) or Fresnel lenses.

[0099] Figure 5b FIG4 shows the state of the first liquid crystal lens unit 120 when it is working. Figure 5b As shown, when the first liquid crystal lens unit 120 is operating, the liquid crystal wave plate 110 is also powered. Linearly polarized light emitted from the display module 50 along the x-axis remains polarized after passing through the liquid crystal wave plate 110. As the first liquid crystal lens unit 120 rubs in the x-direction, it converges the x-axis polarized light. Since the second liquid crystal lens unit rubs in a different direction than the first liquid crystal lens unit, it does not converge the x-axis polarized light. Therefore, the focal length of the display device is determined by the first liquid crystal lens unit 120, resulting in a first focal length.

[0100] Figure 5c FIG4 shows the state of the second liquid crystal lens unit 130 when it is working. Figure 5cAs shown, when the second liquid crystal lens unit 130 is operating, the liquid crystal wave plate 110 is powered off. Linearly polarized light emitted from the display module 50, polarized along the x-axis, rotates by angle α after passing through the liquid crystal wave plate 110. When passing through the first liquid crystal lens unit 120, the incident light is not converged because the rubbing direction of the first liquid crystal lens unit 120 is along the x-axis. However, the second liquid crystal lens unit 130 converges the incident light because its rubbing direction is parallel to the polarization direction of the incident light. Therefore, the focal length of the display device is determined by the second liquid crystal lens unit 130, resulting in a second focal length.

[0101] Reference Figure 5b and Figure 5c When the first liquid crystal lens unit 120 is in operation, the liquid crystal molecules in the second liquid crystal lens unit 130 may be in their initial alignment positions (e.g., the second liquid crystal lens unit 130 has not been driven for a long time), or may be in the process of returning to their initial positions from a certain state. Similarly, when the second liquid crystal lens unit 130 is in operation, the liquid crystal molecules in the first liquid crystal lens unit 120 may be in their initial alignment positions (e.g., the first liquid crystal lens unit 120 has not been driven for a long time), or may be in the process of returning to their initial positions from a certain state. However, for linearly polarized incident light, the phase delay in this polarization direction does not change, and has no effect on the focal length of the system.

[0102] In summary, the liquid crystal lens display device and driving method provided by the present invention, through the provision of liquid crystal wave plates, ensure that the display device always selects one of the two liquid crystal lens groups to operate when switching focal lengths. This ensures that the response time of the liquid crystal lens device depends solely on the power-on response time, that is, solely on the magnitude of the overdrive voltage applied to the liquid crystal lens group. This effectively shortens the response time of the entire liquid crystal lens display device and is suitable for dynamic zoom display. Furthermore, during dynamic zoom, the same response time is maintained regardless of switching from a large focal length to a small focal length or vice versa, thereby improving the display quality and achieving dynamic and smooth image switching.

[0103] In order to intuitively demonstrate the effects of the liquid crystal lens display device 200 disclosed in the embodiment of the present invention, examples are given in combination with relevant technologies.

[0104] Taking a positive focal length liquid crystal lens as an example, assuming a cell thickness of 15 μm and a liquid crystal material rotational viscosity of 0.265 Pa·sec, Table 1 below lists some focal length switching response times for a display device employing this liquid crystal lens (listed only for focal lengths of 1.5 m, 2.0 m, 2.25 m, and 3.0 m) for illustration.

[0105]

[0106]

[0107] Table 1

[0108] For display devices in related technologies, the change in focal length is mainly divided into two situations:

[0109] (1) When zooming from a small focal length to a large focal length, for example, from the current focal length f0 = 1.5m to the target focal length f1 = 2.0m / 2.25m / 3.0m, the "overvoltage-stable" driving method adopted by the present invention can be used to drive the liquid crystal lens to improve the response speed. In this case, the response time of the liquid crystal lens is equal to the power-on response time. The power-on response time varies depending on the overdrive voltage, and the larger the overdrive voltage, the smaller the power-on response time. If a certain overdrive voltage is applied, the power-on response time can be controlled within a certain time, for example, 100ms.

[0110] (2) Zooming from a large focal length to a small focal length, for example, zooming from the current focal length f0 = 3.0m to the target focal length f1 = 2.25m / 2.0m / 1.5m. To speed up the power-off response time of the liquid crystal lens, a voltage of 0 can be applied to the electrodes of the liquid crystal lens until the focal length of the liquid crystal lens switches to f1, and then a stable voltage corresponding to f1 is applied. At this time, the response time of the liquid crystal lens is equal to the time of applying the voltage of 0, that is, the power-off response time for the focal length to switch from f0 to f1. Since the power-off response time is inconsistent with the change in focal length, for example, a power-off response time of 460ms is required to zoom from f0 = 3.0m to f = 1.5m. When the liquid crystal lens has a larger box thickness (or a larger zoom span), the time to zoom from a large focal length to a small focal length may exceed 1s, which will make the switching of the screen appear very jerky and difficult for users to accept.

[0111] Therefore, in the above-mentioned related art, when the display device switches from a large focal length to a small focal length, when the focal length change is large, the response time is too long and inconsistent, seriously affecting the display smoothness during the focal length switching process and seriously affecting the visual experience. However, the liquid crystal lens display device 200 provided by the present invention uses two liquid crystal lens units (a first liquid crystal lens unit 120 and a second liquid crystal lens unit 130). Whether switching from a large focal length to a small focal length or from a small focal length to a large focal length, the response time of the liquid crystal lens assembly 100 depends only on the magnitude of the overdrive voltage. Regardless of whether the cell thickness of the liquid crystal lens is 15 μm or greater, the power-on response time can be shortened by the "overvoltage-stable" driving method. Moreover, the response time for switching between different focal lengths can be kept consistent, for example, controlled within 100 ms or even tens of milliseconds, thereby improving the display quality of the liquid crystal lens display device 200. Table 2 lists the switching response times for the liquid crystal lens display device 200 of the present invention at certain focal lengths (only for focal lengths f = 1.5m / 2.0m / 2.25m / 3.0m) for illustrative purposes. While the response time comparison here is based on positive lenses, the same technical solution has the same characteristics and effects for negative lenses.

[0112]

[0113] Table 2

[0114] Figure 6 A flow chart of a method 300 for driving a liquid crystal lens assembly according to an embodiment of the present invention is shown. Figure 6 Provide detailed explanation.

[0115] Liquid crystal lens components such as Figure 1 The illustrated liquid crystal lens assembly 100 includes a liquid crystal wave plate 110, a first liquid crystal lens unit 120, and a second liquid crystal lens unit 130. The liquid crystal lens assembly 110 is configured to receive image light, which is first linearly polarized light. The liquid crystal wave plate 110 has a first state and a second state. In the first state, the liquid crystal wave plate 110 maintains the polarization direction of the first linearly polarized light passing through it; in the second state, the liquid crystal wave plate 110 rotates the polarization direction of the first linearly polarized light passing through it by a certain angle and emits second linearly polarized light. The first liquid crystal lens unit 120 includes one or more first liquid crystal lenses, each of which is rubbed and aligned along a first direction, which is the same as the polarization direction of the first linearly polarized light. The second liquid crystal lens unit 130 includes one or more second liquid crystal lenses, each of which is rubbed and aligned along a second direction.

[0116] like Figure 3 As shown, the driving method 300 includes the following steps, which are described in detail below.

[0117] In step S310 , the first liquid crystal lens unit is driven to a preset focal length with a preset voltage to switch the liquid crystal wave plate to a first state; or the second liquid crystal lens unit is driven to a preset focal length with a preset voltage to switch the liquid crystal wave plate to a second state.

[0118] In step S320, the target focal length of the liquid crystal lens assembly is determined. This can be determined through eye tracking or gaze tracking. These two methods are mature, efficient, and accurate, and are beneficial for improving the fluidity and accuracy of zooming in the liquid crystal lens assembly.

[0119] In step S330 , one of the first liquid crystal lens unit and the second liquid crystal lens unit is selected, the liquid crystal wave plate is switched to or maintained in the first state or the second state, a driving voltage corresponding to the target focal length is obtained for the selected one, and the selected one is driven by the driving voltage.

[0120] When the first liquid crystal lens unit is selected from the first and second liquid crystal lens units, the liquid crystal wave plate is switched to a first state so that the image light received by the liquid crystal lens assembly is not polarized by the liquid crystal wave plate after passing through the liquid crystal wave plate, and the image light continues to propagate as first linearly polarized light, thereby causing the image light to be converged by the first liquid crystal lens unit but not by the second liquid crystal lens unit. In this case, the focal length of the liquid crystal lens assembly is determined by the first liquid crystal lens unit. When the second liquid crystal lens unit is selected from the first and second liquid crystal lens units, the liquid crystal wave plate is switched to a second state so that the image light received by the liquid crystal lens assembly is polarized by the liquid crystal wave plate (from first linearly polarized light to second linearly polarized light) before entering the first liquid crystal lens unit. This causes the image light to be converged by the second liquid crystal lens unit instead of the first liquid crystal lens unit. In this case, the focal length of the liquid crystal lens assembly is determined by the second liquid crystal lens unit.

[0121] Regarding the selection from the first liquid crystal lens unit and the second liquid crystal lens unit. In this embodiment, the target focal length of the liquid crystal lens assembly can be compared with the current focal length. When the target focal length is greater than or equal to the current focal length, the currently selected one of the first liquid crystal lens unit and the second liquid crystal lens unit is maintained, and the liquid crystal wave plate is maintained in the first state or the second state. When the target focal length is less than the current focal length, the driving voltage of the currently selected one of the first liquid crystal lens unit and the second liquid crystal lens unit is reset to zero, the other one of the first liquid crystal lens unit and the second liquid crystal lens unit is selected, and the liquid crystal wave plate is switched between the first state and the second state, such as the above reference Figure 2 described.

[0122] In another embodiment, the target focal length of the liquid crystal lens assembly can be compared with the current focal length. When the target focal length is the same as the current focal length, the currently selected one of the first liquid crystal lens unit and the second liquid crystal lens unit is maintained, and the liquid crystal wave plate is maintained in the first state or the second state. When the target focal length of the liquid crystal lens assembly is different from the current focal length, the response time for driving the currently selected one of the first liquid crystal lens unit and the second liquid crystal lens unit to the target focal length is determined, and the relationship between the response time and the preset time is determined, wherein the response time can be obtained by real-time calculation or by reading pre-stored information. When the response time is less than or equal to the preset time, the currently selected one of the first liquid crystal lens unit and the second liquid crystal lens unit is maintained, and the liquid crystal wave plate is maintained in the first state or the second state. When the response time is greater than the preset time, the driving voltage of the currently selected one of the first liquid crystal lens unit and the second liquid crystal lens unit is reset to zero, the other one of the first liquid crystal lens unit and the second liquid crystal lens unit is selected, and the liquid crystal wave plate is switched between the first state and the second state, such as the above reference. Figure 3 described.

[0123] According to one embodiment of the present invention, the relationship between the focal length and the driving voltage of the first liquid crystal lens unit, the relationship between the focal length and the driving voltage of the second liquid crystal lens unit, and information about the currently selected one are stored in a storage unit. In the step of obtaining the driving voltage corresponding to the target focal length, the driving voltage corresponding to the target focal length can be obtained by querying the storage unit.

[0124] According to one embodiment of the present invention, a selected one of the first liquid crystal lens unit and the second liquid crystal lens unit may be driven in an “overvoltage-stable” manner to shorten the zoom response time of the liquid crystal lens assembly.

[0125] Finally, it should be noted that the above descriptions are merely embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A liquid crystal lens assembly, comprising: a liquid crystal wave plate having a first state and a second state, wherein in the first state, the liquid crystal wave plate maintains the polarization direction of the first linearly polarized light passing therethrough unchanged; In the second state, the liquid crystal wave plate rotates the polarization direction of the first linearly polarized light passing therethrough by a certain angle and emits a second linearly polarized light; a first liquid crystal lens unit located downstream of the optical path of the liquid crystal wave plate, the focal length of which is adjustable according to a first driving voltage applied to the first liquid crystal lens unit; a second liquid crystal lens unit, located downstream of the optical path of the first liquid crystal lens unit, and having a focal length adjustable according to a second driving voltage applied to the second liquid crystal lens unit; and a control system electrically connected to the liquid crystal wave plate, the first liquid crystal lens unit, and the second liquid crystal lens unit, configured to control the liquid crystal wave plate to switch between a first state and a second state, and to control a first driving voltage applied to the first liquid crystal lens unit and a second driving voltage applied to the second liquid crystal lens unit according to a target focal length of the liquid crystal lens assembly to obtain the target focal length; The control system is configured to: select one of the first liquid crystal lens unit and the second liquid crystal lens unit, switch the liquid crystal wave plate to or maintain it in the first state or the second state, and obtain the target focal length by driving the selected one of the first liquid crystal lens unit and the second liquid crystal lens unit; The control system is configured to: when the target focal length of the liquid crystal lens assembly is greater than the current focal length, increase the driving voltage of the currently selected one of the first and second liquid crystal lens units to achieve the target focal length; when the target focal length of the liquid crystal lens assembly is less than the current focal length, switch the liquid crystal wave plate between the first and second states, reset the driving voltage of the currently selected one to zero, select the other, and increase the driving voltage of the other to achieve the target focal length; or, when the target focal length of the liquid crystal lens assembly is different from the current focal length, determine a response time for driving the selected one of the first and second liquid crystal lens units to the target focal length; determine a relationship between the response time and a preset time; when the response time is less than the preset time, drive the selected one to achieve the target focal length; and if the response time is greater than the preset time, switch the liquid crystal wave plate between the first and second states, reset the driving voltage of the currently selected one to zero, select the other, and increase the driving voltage of the other to achieve the target focal length.

2. The liquid crystal lens assembly according to claim 1, wherein the control system comprises: a control unit configured to determine the first driving voltage and the second driving voltage according to a target focal length of the liquid crystal lens assembly; A driving unit is connected to the control unit, the first liquid crystal lens unit, and the second liquid crystal lens unit, respectively, and is configured to apply the first driving voltage and the second driving voltage to the first liquid crystal lens unit and the second liquid crystal lens unit, respectively.

3. The liquid crystal lens assembly according to claim 1, wherein the first liquid crystal lens unit includes one or more first liquid crystal lenses, and the second liquid crystal lens unit includes one or more second liquid crystal lenses, wherein the first liquid crystal lenses are rubbed and aligned along a first direction, and the second liquid crystal lenses are rubbed and aligned along a second direction, the first direction is the same as the polarization direction of the first linearly polarized light, and the second direction is the same as the polarization direction of the second linearly polarized light.

4. The liquid crystal lens assembly according to claim 3, wherein: An included angle between the first direction and the second direction is 70-110°. 5 . The liquid crystal lens assembly according to claim 1 , further comprising a tracking unit configured to determine the target focal length by eye tracking or gaze tracking.

6. The liquid crystal lens assembly according to claim 1 , further comprising a storage unit that stores a relationship between a focal length of the first liquid crystal lens cell and a first driving voltage, and a relationship between a focal length of the second liquid crystal lens cell and a second driving voltage, and further stores information on which one of the first and second liquid crystal lens cells is currently selected.

7. The liquid crystal lens assembly according to claim 1, wherein the control system is configured to: switch the liquid crystal wave plate to the first state when the first liquid crystal lens cell is selected from the first and second liquid crystal lens cells; and switch the liquid crystal wave plate to the second state when the second liquid crystal lens cell is selected from the first and second liquid crystal lens cells.

8. The liquid crystal lens assembly according to claim 1, wherein: The control system is configured to calculate or read the pre-stored response time in real time.

9. The liquid crystal lens assembly according to claim 1 , wherein the control system is configured to drive the first liquid crystal lens unit and the second liquid crystal lens unit in an “overvoltage-stable” manner.

10. A liquid crystal lens display device comprising: A display module is used to emit image light, wherein the image light is a first linearly polarized light. ； The liquid crystal lens assembly according to any one of claims 1 to 9, wherein the liquid crystal lens assembly is arranged downstream of the optical path of the display module to receive and project the first linearly polarized light.

11. A method for driving a liquid crystal lens assembly, wherein the liquid crystal lens assembly comprises a liquid crystal wave plate, a first liquid crystal lens unit, and a second liquid crystal lens unit, the method comprising: driving the first liquid crystal lens unit to a preset focal length with a preset voltage, switching the liquid crystal wave plate to a first state, or driving the second liquid crystal lens unit to a preset focal length with a preset voltage, switching the liquid crystal wave plate to a second state; determining a target focal length of the liquid crystal lens assembly; selecting one of the first liquid crystal lens unit and the second liquid crystal lens unit, switching the liquid crystal wave plate to or maintaining it in the first state or the second state, obtaining a driving voltage corresponding to the target focal length for the selected one, and driving the selected one with the driving voltage; The step of selecting one of the first liquid crystal lens unit and the second liquid crystal lens unit to switch the liquid crystal wave plate to or maintain the liquid crystal wave plate in the first state or the second state comprises: When the target focal length of the liquid crystal lens assembly is greater than the current focal length, maintaining the currently selected one and maintaining the liquid crystal wave plate in the first state or the second state; When the target focal length of the liquid crystal lens assembly is less than the current focal length, the driving voltage of the currently selected one is reset to zero, another one is selected, and the liquid crystal wave plate is switched between the first state and the second state; Alternatively, the step of selecting one of the first liquid crystal lens unit and the second liquid crystal lens unit to switch the liquid crystal wave plate to or maintain it in the first state or the second state includes: When the target focal length of the liquid crystal lens assembly is different from the current focal length, determining a response time for driving the selected one of the first liquid crystal lens unit and the second liquid crystal lens unit to the target focal length; Determining the relationship between the response time and a preset time; When the response time is less than the preset time, keeping the currently selected one, and keeping the liquid crystal wave plate in the first state or the second state; If the response time is greater than the preset time, the driving voltage of the currently selected one is reset to zero, another one is selected, and the liquid crystal wave plate is switched between the first state and the second state.

12. The driving method according to claim 11, further comprising: The target focal length is determined by eye tracking or gaze tracking.

13. The driving method according to claim 11 , wherein the relationship between the focal length and the driving voltage of the first liquid crystal lens unit, the relationship between the focal length and the driving voltage of the second liquid crystal lens unit, and information of the currently selected one are stored in a storage unit; The step of obtaining a driving voltage corresponding to the target focal length comprises: By querying the storage unit, a driving voltage corresponding to the target focal length is obtained.

14. The driving method according to claim 11, wherein when the first liquid crystal lens unit is selected from the first liquid crystal lens unit and the second liquid crystal lens unit, the liquid crystal wave plate is switched to the first state; when the second liquid crystal lens unit is selected from the first liquid crystal lens unit and the second liquid crystal lens unit, the liquid crystal wave plate is switched to the second state.

15. The driving method according to claim 11 , wherein the liquid crystal lens assembly is configured to receive first linearly polarized light, the first liquid crystal lens unit comprises one or more first liquid crystal lenses, and the second liquid crystal lens unit comprises one or more second liquid crystal lenses, wherein the first liquid crystal lenses are rubbed and aligned along a first direction, and the second liquid crystal lenses are rubbed and aligned along a second direction, the first direction being the same as the polarization direction of the first linearly polarized light, and the driving method further comprising: When the second liquid crystal lens is selected, the polarization direction of the first linearly polarized light is rotated to the second direction by the liquid crystal wave plate before entering the first liquid crystal lens unit.

16. The driving method according to claim 11, wherein the step of driving the selected one with the driving voltage comprises: The selected one is driven in an "overvoltage-stable" manner.

Images