Driving method of liquid crystal grating, display device and display method thereof

Abstract

The driving method of the liquid crystal grating provided by the present disclosure, a display device, and its display method include determining the real-time position of the pupil center; determining the position of the light-transmitting area corresponding to the real-time position in the liquid crystal grating according to the real-time position and the pre-established correspondence between the position of the pupil center and the position of the light-transmitting area in the liquid crystal grating; driving the liquid crystal grating so that the liquid crystal grating transmits light only at the position of the light-transmitting area corresponding to the real-time position.

Description

Technical Field

[0001] The present disclosure relates to the field of display technologies, and in particular, to a driving method for a liquid crystal grating, a display device, and a display method thereof. Background Art

[0002] With the continuous development of display technologies, three-dimensional (3D) display technologies have attracted increasing attention. The working principle of 3D display technologies is as follows: for the same scene, the left and right eyes of a viewer respectively receive images. The distance between the left and right eyes of the viewer in the horizontal direction (i.e., the interpupillary distance, about 65 mm) causes a slight difference in the viewing angles of the two eyes. Due to this difference, the images observed by the left and right eyes of the viewer will also be slightly different (i.e., binocular parallax). After the left-eye image and the right-eye image are superimposed and fused by the visual cortex of the brain, a stereoscopic effect is formed. Summary of the Invention

[0003] The present disclosure provides a driving method for a liquid crystal grating, a display device, and a display method thereof. The specific solutions are as follows:

[0004] On the one hand, an embodiment of the present disclosure provides a driving method for a liquid crystal grating, including:

[0005] Determining the real-time position of the pupil center;

[0006] According to the real-time position and the pre-established correspondence between the position of the pupil center and the position of the light-transmitting region in the liquid crystal grating, determining the position of the light-transmitting region corresponding to the real-time position in the liquid crystal grating;

[0007] Driving the liquid crystal grating so that the liquid crystal grating transmits light only at the position of the light-transmitting region corresponding to the real-time position.

[0008] In some embodiments, in the above driving method provided by the embodiment of the present disclosure, determining the real-time position of the pupil center specifically includes: real-time collecting a facial image of a user, and determining the three-dimensional coordinates of the pupil center in the camera coordinate system based on the facial image.

[0009] In some embodiments, in the above driving method provided by the embodiment of the present disclosure, real-time collecting a facial image of a user, and determining the three-dimensional coordinates of the pupil center in the camera coordinate system based on the facial image specifically includes:

[0010] Respectively collecting facial images in real time by visible light cameras with different positions;

[0011] Respectively extracting a plurality of first edge points of the iris in the facial images collected simultaneously by each of the visible light cameras, and matching the first edge points at the same position in each of the facial images;

[0012] Calculate the three-dimensional coordinates of each of the successfully matched first edge points in the camera coordinate system using triangulation;

[0013] Use the three-dimensional coordinates of the center of the mapped space of each of the first edge points in the camera coordinate system as the three-dimensional coordinates of the pupil center in the camera coordinate system.

[0014] In some embodiments, in the above driving method provided by the embodiments of the present disclosure, a facial image of a user is collected in real time, and the three-dimensional coordinates of the pupil center in the camera coordinate system are determined based on the facial image, specifically including:

[0015] Use an infrared camera to obtain a facial image of the user in real time;

[0016] Extract multiple first edge points of the iris in the facial image, and perform elliptical fitting on the multiple first edge points. Use the two-dimensional coordinates of the center of the fitted ellipse in the image coordinate system as the two-dimensional coordinates of the pupil center in the image coordinate system;

[0017] Obtain multiple facial feature points in the facial image, and map the multiple facial feature points to the same positions on a pre-established three-dimensional human face model;

[0018] Adjust the coordinate system of the three-dimensional human face model to coincide with the camera coordinate system;

[0019] Use the mean or mode of the depth coordinates of multiple second edge points of the human eye in the three-dimensional human face model in the camera coordinate system as the depth coordinates of the pupil center in the camera coordinate system;

[0020] Convert the two-dimensional coordinates of the pupil center in the image coordinate system into two-dimensional coordinates of the same dimension of the pupil center in the camera coordinate system. The two-dimensional coordinates of the pupil center in the camera coordinate system and the depth coordinates of the pupil center in the camera coordinate system constitute the three-dimensional coordinates of the pupil center in the camera coordinate system.

[0021] In some embodiments, in the above driving method provided by the embodiments of the present disclosure, establishing a three-dimensional human face model specifically includes:

[0022] Use a visible light camera to collect at least one facial image;

[0023] Obtain multiple facial feature points of each facial image;

[0024] Calculate the three-dimensional coordinates of the multiple facial feature points in the camera coordinate system using triangulation;

[0025] Take one of the facial feature points as the origin of the coordinate system of the to-be-established three-dimensional human face model, and adjust the origin of the coordinate system of the to-be-established three-dimensional human face model to coincide with the origin of the camera coordinate system, so that the three-dimensional coordinates of the multiple facial feature points in the camera coordinate system are converted into the three-dimensional coordinates in the coordinate system of the to-be-established three-dimensional human face model;

[0026] According to the three-dimensional coordinates of the multiple facial feature points in the coordinate system of the to-be-established three-dimensional human face model, restore the three-dimensional face represented by the multiple facial feature points, and realize the establishment of the three-dimensional human face model.

[0027] In some embodiments, in the above driving method provided by the embodiments of the present disclosure, establishing the correspondence between the position of the pupil center and the position of the light-transmitting area in the liquid crystal grating specifically includes:

[0028] Take the center of the liquid crystal grating as the origin of the coordinate system, the light-emitting direction of the liquid crystal grating as the positive direction of the Z axis, and the negative direction of the X axis of the camera coordinate system as the positive direction of the X axis to establish the coordinate system of the liquid crystal grating;

[0029] In the coordinate system of the liquid crystal grating, determine the light-transmitting areas at different positions in the liquid crystal grating corresponding to different positions of the pupil center.

[0030] In some embodiments, in the above driving method provided by the embodiments of the present disclosure, according to the real-time position and the pre-established correspondence between the position of the pupil center and the position of the light-transmitting area in the liquid crystal grating, determining the position of the light-transmitting area corresponding to the real-time position in the liquid crystal grating specifically includes:

[0031] Take the negative value of the x coordinate of the pupil center determined in real time in the camera coordinate system as the x coordinate of the pupil center in the coordinate system of the liquid crystal grating, and take the z coordinate of the pupil center determined in real time in the camera coordinate system as the z coordinate of the pupil center in the coordinate system of the liquid crystal grating;

[0032] Judge whether the z coordinate of the pupil center in the coordinate system of the liquid crystal grating is equal to the preset optimal viewing distance; if so, move the light-transmitting area in the X-axis direction of the coordinate system of the liquid crystal grating, and the size of the moved light-transmitting area is the same as that of the light-transmitting area before movement; if not, adjust the size of the light-transmitting area in the X-axis direction of the coordinate system of the liquid crystal grating, and the position of the adjusted light-transmitting area partially overlaps with the position of the light-transmitting area before adjustment.

[0033] In some embodiments, in the above driving method provided by the embodiments of the present disclosure, moving the light-transmitting area in the X-axis direction of the coordinate system of the liquid crystal grating specifically includes:

[0034] Detecting the coordinate point of the pupil center in the coordinate system of the liquid crystal grating, the coordinates of the intersection of the extended line of the origin and the liquid crystal grating;

[0035] The x-coordinate of the intersection coordinate is compared with the coordinates of the endpoints on the same side of each strip electrode in one period in the liquid crystal grating on the x-axis. If the x-coordinate of the intersection coordinate is greater than the coordinates of the endpoints of the (i-1)th strip electrode in one period and is less than or equal to the coordinates of the endpoints of the i-th strip electrode, then the area where the i-th to [(i+n / 2)-1]th strip electrodes in each period are located is determined to be the light-transmitting area corresponding to the current pupil center, n is the total number of strip electrodes in a periphery and n is an even number, and i is an integer greater than or equal to 2 and less than or equal to n / 2.

[0036] In some embodiments, in the driving method provided in the embodiments of the present disclosure, adjusting the size of the light-transmitting area in the X-axis direction of the coordinate system of the liquid crystal grating specifically includes:

[0037] Calculate the position coordinates of each strip electrode on the X-axis within a total of m periods, the coordinate range of the light-transmitting area corresponding to each left-eye pixel in the liquid crystal grating on the X-axis, and the coordinate range of the light-transmitting area corresponding to each right-eye pixel in the liquid crystal grating on the X-axis;

[0038] The position coordinates of the bth strip electrode in the ath period are compared with the coordinate range of the light-transmitting area corresponding to the left-eye pixel and the coordinate range of the light-transmitting area corresponding to the right-eye pixel. If the position coordinates of the bth strip electrode in the ath period are both within the coordinate range of the light-transmitting area corresponding to the left-eye pixel and the coordinate range of the light-transmitting area corresponding to the right-eye pixel, then the area where the bth strip electrode in the ath period is located is determined to be the light-transmitting area corresponding to the current pupil center, m is the total number of grating periods in the liquid crystal grating, a is an integer greater than or equal to 1 and less than or equal to m, and b is an integer greater than or equal to 1 and less than or equal to n.

[0039] On the other hand, an embodiment of the present disclosure provides a display device, including a backlight source, a liquid crystal panel located on the light-emitting side of the backlight source, and a liquid crystal grating located between the backlight source and the liquid crystal panel, wherein the liquid crystal grating is driven using the above-mentioned driving method provided in the embodiment of the present disclosure.

[0040] On the other hand, an embodiment of the present disclosure provides a display method of the above display device, comprising:

[0041] In the two-dimensional display mode, the liquid crystal grating is controlled to be completely light-transmissive;

[0042] In the three-dimensional display mode, the above driving method is used to control the liquid crystal grating to form light-transmitting areas and light-shielding areas that are alternately arranged.

[0043] In some embodiments, in the above display method provided by the embodiments of the present disclosure, while adjusting the size of the light-transmitting region in the X-axis direction of the coordinate system of the liquid crystal grating, the following is further included:

[0044] Determine the total number of strip electrodes corresponding to the light-transmitting region, and adjust the backlight brightness emitted by the backlight source based on the total number of strip electrodes. The backlight brightness has a negative correlation with the total number of strip electrodes. Description of the Drawings

[0045] Figure 1 It is a flowchart of the driving method of the liquid crystal grating provided by the embodiments of the present disclosure;

[0046] Figure 2 It is a schematic diagram of collecting a facial image provided by the embodiments of the present disclosure;

[0047] Figure 3 It is a flowchart of determining the real-time position of the pupil center provided by the embodiments of the present disclosure;

[0048] Figure 4 It is a schematic structural diagram of a display device provided by the embodiments of the present disclosure;

[0049] Figure 5 It is another flowchart of determining the real-time position of the pupil center provided by the embodiments of the present disclosure;

[0050] Figure 6 It is a flowchart of establishing a three-dimensional face model provided by the embodiments of the present disclosure;

[0051] Figure 7 It is a flowchart of establishing the corresponding relationship between different positions of the pupil center and different positions of the light-transmitting region in the liquid crystal grating provided by the embodiments of the present disclosure;

[0052] Figure 8 It is a schematic diagram of establishing the coordinate system of the liquid crystal grating provided by the embodiments of the present disclosure;

[0053] Figure 9 It is a flowchart of determining the position of the light-transmitting region corresponding to the real-time position of the pupil center in the liquid crystal grating provided by the embodiments of the present disclosure;

[0054] Figure 10 It is a schematic diagram of moving the position of the light-transmitting region to the left according to the real-time position of the pupil center provided by the embodiments of the present disclosure;

[0055] Figure 11 It is a schematic diagram of reducing the size of the light-transmitting region according to the real-time position of the pupil center provided by the embodiments of the present disclosure;

[0056] Figure 12 It is a flowchart of adjusting the size of the light-transmitting region provided by the embodiments of the present disclosure. Detailed Description of the Embodiments

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. It should be noted that the sizes and shapes of the various figures in the accompanying drawings do not reflect the true proportions, and the purpose is only to schematically illustrate the content of the present disclosure. Also, the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. To keep the following description of the embodiments of the present disclosure clear and concise, detailed descriptions of known functions and known components are omitted in the present disclosure.

[0058] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art to which the present disclosure pertains. The terms "first", "second", and similar terms used in the specification and claims of the present disclosure do not denote any order, quantity, or importance, but are only used to distinguish different components. The terms "including" or "comprising" and similar terms mean that the elements or items appearing before the term cover the elements or items listed after the term and their equivalents, without excluding other elements or items. The terms "inside", "outside", "above", "below", etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0059] The naked-eye 3D display technology is a display technology that utilizes the characteristic of binocular parallax to obtain a realistic three-dimensional image with space and depth without the need for any auxiliary devices (such as 3D glasses). Due to the advantages of the three-dimensional images displayed by the naked-eye 3D display device, such as real and vivid expressiveness, good environmental infectivity, and strong visual impact, the application scenarios of the naked-eye 3D display device are becoming more and more extensive.

[0060] The related naked-eye 3D display technology is mainly based on the stereoscopic display method of viewpoints, and its light splitting devices mainly include two types: the barrier type and the lenticular type. Among them, the light splitting device of the barrier type can be a liquid crystal grating. The liquid crystal grating includes a first substrate and a second substrate arranged opposite to each other, and a liquid crystal layer located between the first substrate and the second substrate. The side of the first substrate facing the liquid crystal layer has a plurality of strip-shaped electrodes, and the side of the second substrate facing the liquid crystal layer has a planar electrode. By applying voltages to the planar electrode and some of the strip-shaped electrodes, a light-transmitting area and a light-blocking area can be alternately formed in the liquid crystal grating. Since the liquid crystal grating has good compatibility with the liquid crystal panel, the application of the naked-eye 3D display technology based on the liquid crystal grating is becoming more and more widespread. For example, there are related demands in the fields of entertainment, education, vehicle-mounted, medical, etc. However, the naked-eye 3D display technology based on the liquid crystal grating is restricted by the fixed viewing angle and viewing distance, which seriously affects its popularization and application.

[0061] To solve the above technical problems existing in the related art, an embodiment of the present disclosure provides a driving method for a liquid crystal grating, as Figure 1 shown, including:

[0062] S101. Determine the real-time position of the pupil center;

[0063] S102. According to the real-time position and the pre-established correspondence between the position of the pupil center and the position of the light-transmitting area in the liquid crystal grating, determine the position of the light-transmitting area corresponding to the real-time position in the liquid crystal grating;

[0064] S103. Drive the liquid crystal grating so that the liquid crystal grating transmits light only at the position of the light-transmitting area corresponding to the real-time position.

[0065] In the driving method for the liquid crystal grating provided by the embodiment of the present disclosure, after determining the real-time position of the pupil center and determining the position of the light-transmitting area corresponding to the real-time position in the liquid crystal grating according to the real-time position and the pre-established correspondence between the position of the pupil center and the position of the light-transmitting area in the liquid crystal grating, the liquid crystal grating is controlled to transmit light only at the position of the light-transmitting area corresponding to the real-time position, so that the user can view 3D images at different distances and different viewing angles, thereby removing the limitation that the naked-eye 3D device can only be viewed at a fixed viewing angle and a fixed distance, which is conducive to the popularization and application of the naked-eye 3D display technology based on the liquid crystal grating.

[0066] In some embodiments, in the above driving method provided by the embodiment of the present disclosure, the above step S101, determining the real-time position of the pupil center, can be specifically implemented in the following manner: Real-time collect the facial image of the user, and determine the three-dimensional coordinates of the pupil center in the camera coordinate system based on the facial image to achieve accurate positioning of the pupil center.

[0067] Visible light images usually have a high spatial resolution (i.e., the smallest distinguishable detail in the image), can present more detailed information, and have a good contrast effect between light and dark. Therefore, visible light images are suitable for human visual perception. Based on this, in some embodiments, as Figure 2 shown, the facial image of the user can be collected by the imaging element C, such as a visible light (RGB) camera, etc. In this case, the above steps: Real-time collect the facial image of the user, and determine the three-dimensional coordinates of the pupil center in the camera coordinate system based on the facial image, can be specifically implemented through Figure 3 the steps shown as follows:

[0068] S1011. Use visible light cameras with different positions to respectively collect facial images in real time;

[0069] Exemplarily, as Figure 4As shown, there can be two visible light cameras, and the two visible light cameras can be symmetrically distributed on both sides of the central axis S of the liquid crystal panel P. Correspondingly, the optical centers O of the two cameras can be symmetric about the central axis S of the liquid crystal panel P;

[0070] S1012. Respectively extract multiple first edge points of the iris in the face images simultaneously collected by each visible light camera, and match the first edge points at the same position in each face image; in different face images, if there are first edge points at the same position of the iris, it is considered that the first edge points of the iris at this position in different images are successfully matched, and all the successfully matched first edge points form the edge of the iris;

[0071] S1013. Use the triangulation method to calculate the three-dimensional coordinates of each successfully matched first edge point in the camera coordinate system, which is equivalent to converting the two-dimensional coordinates of each first edge point of the iris in the image coordinate system into three-dimensional coordinates in the camera coordinate system; among them, triangulation is a method in visual positioning to find the 3D position of a point given the positions of multiple cameras and the projection points of a point in space.

[0072] S1014. Take the three-dimensional coordinates of the center of the mapping space of each first edge point in the camera coordinate system as the three-dimensional coordinates of the pupil center in the camera coordinate system. Under normal circumstances, the iris and the pupil are not strictly concentric circles, but in general their centers are very close, so it is approximately processed as having the same center, and the pupil center can be found by locating the center of the iris. Therefore, the three-dimensional coordinates of the center of the mapping space of each first edge point in the camera coordinate system can be used as the three-dimensional coordinates of the pupil center in the camera coordinate system.

[0073] Considering that under certain harsh conditions (such as strong light, fog, etc.), the visible light image is easily affected and an ideal visible light image cannot be obtained. On the contrary, the infrared image depicting the thermal radiation of an object can effectively resist these interferences. Based on this, in some embodiments, the imaging element C can also be an infrared (IR) camera, etc., to collect the face image of the user. In this case, the above steps: real-time collect the face image of the user and determine the three-dimensional coordinates of the pupil center in the camera coordinate system based on the face image, can be specifically implemented through Figure 5 the steps shown as follows:

[0074] S1011'. Use an infrared camera to obtain the face image of the user in real time;

[0075] S1012'. Extract multiple first edge points of the iris in the face image, and perform elliptical fitting on the multiple first edge points. The two-dimensional coordinates of the center of the fitted ellipse in the image coordinate system are used as the two-dimensional coordinates of the pupil center in the image coordinate system;

[0076] S1013': Obtain multiple facial feature points in the facial image, and map the multiple facial feature points to the same positions on a pre-established three-dimensional human face model; optionally, the facial feature points are points that can reflect facial features such as eyebrows, eyes, nose, mouth, face shape contour, etc.;

[0077] S1014': Adjust the coordinate system of the three-dimensional human face model to coincide with the camera coordinate system; optionally, the rotation vector and translation vector from the coordinate system of the three-dimensional human face model to the camera coordinate system can be obtained based on the pose measurement method of PnP. Rotate the xyz coordinate axes of the coordinate system of the three-dimensional human face model according to the obtained rotation vector and translate the origin of the coordinate system of the three-dimensional human face model according to the obtained translation vector, so that the coordinate system of the three-dimensional human face model coincides with the camera coordinate system;

[0078] S1015': Use representative data such as the mean or mode of the depth coordinates of multiple second edge points of the human eyes in the three-dimensional human face model in the camera coordinate system as the depth coordinate of the pupil center in the camera coordinate system;

[0079] S1016': Convert the two-dimensional coordinate of the pupil center in the image coordinate system to the two-dimensional coordinate of the pupil center in the camera coordinate system. The two-dimensional coordinate of the pupil center in the camera coordinate system and the depth coordinate of the pupil center in the camera coordinate system constitute the three-dimensional coordinate of the pupil center in the camera coordinate system. Each camera has camera internal parameters (such as parameters like the optical center, focal length, etc.). Combining the camera internal parameters, the two-dimensional coordinates (i.e., xy coordinates) of each point in the image captured by the camera in the image coordinate system can be converted to the two-dimensional coordinates (i.e., xy coordinates) of the same dimension in the camera coordinate system.

[0080] In some embodiments, in the above driving method provided by the embodiments of the present disclosure, as Figure 6 shown, to establish a three-dimensional human face model, it can be specifically implemented in the following ways:

[0081] S601: Use a visible light camera to collect at least one facial image; in some embodiments, multiple frames of facial images can be collected by two visible light cameras;

[0082] S602: Obtain multiple facial feature points of each facial image;

[0083] S603: Use the triangulation method to calculate the three-dimensional coordinates of multiple facial feature points in the camera coordinate system;

[0084] S604. Use one of the facial feature points (such as the tip of the nose, pupil, etc.) as the origin of the coordinate system of the three-dimensional human face model to be established, and through the pose measurement method of PnP, adjust the origin of the coordinate system of the three-dimensional human face model to be established to coincide with the origin of the camera coordinate system, so that the three-dimensional coordinates of multiple facial feature points in the camera coordinate system are converted into three-dimensional coordinates in the coordinate system of the three-dimensional human face model to be established;

[0085] S605. According to the three-dimensional coordinates of multiple facial feature points in the coordinate system of the three-dimensional human face model to be established, restore the three-dimensional face represented by multiple facial feature points to establish the three-dimensional human face model.

[0086] In some embodiments, in the above driving method provided by the embodiments of the present disclosure, as Figure 7 shown, establish the corresponding relationship between the position of the pupil center and the position of the light-transmitting area in the liquid crystal grating, which can be specifically implemented in the following ways:

[0087] S701. Take the center of the liquid crystal grating as the origin of the coordinate system, the light-emitting direction of the liquid crystal grating (equivalent to the positive direction of the Z axis of the camera coordinate system) as the positive direction of the Z axis, and the negative direction of the X axis of the camera coordinate system as the positive direction of the X axis to establish the coordinate system of the liquid crystal grating, as Figure 8 shown; the liquid crystal grating is located between the liquid crystal panel and the backlight source, D is the optimal viewing distance of the human eye from the liquid crystal panel, and h is the distance between the liquid crystal panel and the liquid crystal grating considering the refractive index at the optimal viewing distance; the center of the liquid crystal grating coincides approximately with the center of the liquid crystal panel (i.e., exactly coincides, or within the error range caused by factors such as alignment and measurement), and the light-emitting direction of the liquid crystal grating is the direction from the liquid crystal grating to the liquid crystal panel;

[0088] S702. In the coordinate system of the liquid crystal grating, determine the light-transmitting areas at different positions in the liquid crystal grating corresponding to the pupil center at different positions.

[0089] In some embodiments, in the above driving method provided by the embodiments of the present disclosure, step S102. According to the real-time position and the pre-established corresponding relationship between the position of the pupil center and the position of the light-transmitting area in the liquid crystal grating, determine the position of the light-transmitting area corresponding to the real-time position in the liquid crystal grating, which may specifically include the following steps, as Figure 9 shown:

[0090] S901. Take the negative value of the x coordinate of the pupil center determined in real time in the camera coordinate system as the x coordinate of the pupil center in the coordinate system of the liquid crystal grating, and take the z coordinate of the pupil center determined in real time in the camera coordinate system as the z coordinate of the pupil center in the coordinate system of the liquid crystal grating to realize the conversion of the coordinates of the pupil center from the camera coordinate system to the coordinate system of the liquid crystal grating;

[0091] S902. Determine whether the z - coordinate of the pupil center in the coordinate system of the liquid crystal grating is equal to the preset optimal viewing distance D. If so, it can be determined that the human eye is moving left and right on the X - axis ( Figure 10 as shown in the human eye moving left), and it is necessary to move the light - transmitting area in the X - axis direction of the coordinate system of the liquid crystal grating ( Figure 10 as shown in moving the light - transmitting area to the left), and the size of the light - transmitting area after movement is the same as that before movement. For example, the overall light - transmittance of the light - transmitting area in the liquid crystal grating is 50%, and the size of each light - transmitting area is the same. If not, it can be determined that the human eye is moving forward and backward on the Y - axis ( Figure 11 as shown in the human eye approaching the liquid crystal panel), and adjust the size of the light - transmitting area in the X - axis direction of the coordinate system of the liquid crystal grating ( Figure 11 as shown in reducing the light - transmitting area), and the light - transmitting area after adjustment partially overlaps with the light - transmitting area before adjustment.

[0092] In some embodiments, in the above - mentioned driving method provided by the embodiments of the present disclosure, moving the light - transmitting area in the X - axis direction of the coordinate system of the liquid crystal grating can be specifically implemented in the following manner:

[0093] Detect the intersection coordinates of the extension line of the connection line between the coordinate point of the pupil center in the coordinate system of the liquid crystal grating and the origin and the liquid crystal grating; and make the x - coordinate x of the intersection coordinates open be compared with the endpoint coordinates on the same side (such as the left side or the right side) of the X - axis of each strip - shaped electrode within one period in the liquid crystal grating. If the x - coordinate x of the intersection coordinates open is greater than the endpoint coordinate x of the (i - 1)th strip - shaped electrode within one period i-1 and less than or equal to the endpoint coordinate x of the ith strip - shaped electrode i , then determine that the area where the ith to [(i + n / 2)-1]th strip - shaped electrodes are located within each period is the light - transmitting area corresponding to the current pupil center, where n is the total number of strip - shaped electrodes within one period and n is an even number, and i is an integer greater than or equal to 2 and less than or equal to n / 2.

[0094] Among the multiple strip - shaped electrodes in the liquid crystal grating, taking n strip - shaped electrodes as one period, the strip - shaped electrodes corresponding to the same digit in all periods are connected together. Therefore, the light - transmitting situation of the liquid crystal grating within each period is the same, and only the voltage - applying situation of the strip - shaped electrodes within one period needs to be calculated. Taking the left - eye pupil center as an example, the extension line of the connection line between the coordinate point of the left - eye pupil center in the coordinate system of the liquid crystal grating and the origin of the coordinate system of the liquid crystal grating intersects the liquid crystal grating at a point. Compare the left - endpoint coordinate x of each strip - shaped electrode in the X - axis direction i with the coordinate x of this point open . If x i-1 <x open ≤x i, it can be known that the positions of the i-th to (i + n / 2)-1th strip electrodes within one period need to be set to the light-transmitting state.

[0095] In some embodiments, in the above driving method provided by the embodiments of the present disclosure, to adjust the size of the light-transmitting area in the X-axis direction of the coordinate system of the liquid crystal grating, it can be specifically implemented in the following manner, such as Figure 12 shown as follows:

[0096] Calculate the position coordinates of each strip electrode on the X-axis within a total of m periods, the coordinate range of the light-transmitting area corresponding to each left-eye pixel in the liquid crystal grating on the X-axis, and the coordinate range of the light-transmitting area corresponding to each right-eye pixel in the liquid crystal grating on the X-axis;

[0097] Compare the position coordinates of the b-th strip electrode in the a-th period with the coordinate range of the light-transmitting area corresponding to the left-eye pixel and the coordinate range of the light-transmitting area corresponding to the right-eye pixel. If the position coordinates of the b-th strip electrode in the a-th period are simultaneously within the coordinate range of the light-transmitting area corresponding to the left-eye pixel and the coordinate range of the light-transmitting area corresponding to the right-eye pixel, that is, the position coordinates of the b-th strip electrode in the a-th period are within the intersection of the coordinate range of the light-transmitting area corresponding to the left-eye pixel and the coordinate range of the light-transmitting area corresponding to the right-eye pixel, then determine that the area where the b-th strip electrode is located in the a-th period is the light-transmitting area corresponding to the current pupil center. m is the total number of grating periods in the liquid crystal grating, a is an integer greater than or equal to 1 and less than or equal to m, and b is an integer greater than or equal to 1 and less than or equal to n.

[0098] Based on the same inventive concept, the embodiments of the present disclosure also provide a display device, including a backlight source, a liquid crystal panel located on the light-emitting side of the backlight source, and a liquid crystal grating located between the backlight source and the liquid crystal panel. The liquid crystal grating is driven by the above driving method provided by the embodiments of the present disclosure. Since the principle of solving problems of this display device is similar to that of the above driving method, therefore, the implementation of this display device provided by the embodiments of the present disclosure can refer to the implementation of the above driving method provided by the embodiments of the present disclosure, and the repeated parts will not be described again.

[0099] In some embodiments, the display device provided by the embodiments of the present disclosure may be: any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, a smart watch, a fitness bracelet, a personal digital assistant, etc. The display device includes, but is not limited to: a radio frequency unit, a network module, an audio output & input unit, a sensor, a display unit, a user input unit, an interface unit, a memory, a processor, and a power supply, etc. In addition, those skilled in the art can understand that the above structure does not constitute a limitation on the display device provided by the embodiments of the present disclosure. In other words, the display device provided by the embodiments of the present disclosure may include more or fewer components as described above, or combine certain components, or have different component arrangements.

[0100] Based on the same inventive concept, the embodiments of the present disclosure also provide a display method for the above display device, including the following steps:

[0101] In the two-dimensional display mode, control the liquid crystal grating to be completely transparent.

[0102] In the three-dimensional display mode, use the above driving method provided by the embodiments of the present disclosure to control the liquid crystal grating to form alternately arranged light-transmitting areas and light-blocking areas.

[0103] In some embodiments, when in the three-dimensional display mode, the backlight is inevitably blocked by the light-blocking areas in the liquid crystal grating, resulting in a decrease in the screen brightness. And when the human eye moves forward (i.e., moves towards the direction close to the liquid crystal panel), the light-transmitting areas of the liquid crystal grating shrink, and the screen brightness will be even lower. Therefore, to ensure the screen brightness, it is necessary to increase the backlight brightness. Optionally, in the present disclosure, while adjusting the size of the light-transmitting areas in the X-axis direction of the coordinate system of the liquid crystal grating, determine the total number of strip electrodes corresponding to the light-transmitting areas, and adjust the backlight brightness emitted by the backlight source based on the total number of strip electrodes. The backlight brightness has a negative correlation with the total number of strip electrodes, that is, the smaller the light-transmitting area, the fewer the number of strip electrodes, and the greater the backlight brightness needs to be increased.

[0104] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present disclosure without departing from the spirit and scope of the embodiments of the present disclosure. Thus, if these modifications and variations of the embodiments of the present disclosure fall within the scope of the claims of the present disclosure and their equivalent technologies, the present disclosure also intends to include these changes and modifications.

Claims

1. A driving method of a liquid crystal grating, wherein, Comprising: Determine the real-time position of the pupil center; The pupil center includes the left-eye pupil center and the right-eye pupil center; According to the real-time position and the pre-established correspondence between the position of the pupil center and the position of the light-transmitting area in the liquid crystal grating, determine the position of the light-transmitting area corresponding to the real-time position in the liquid crystal grating; Wherein, determining the position of the light-transmitting area corresponding to the real-time position in the liquid crystal grating specifically includes: Judge whether the distance between the pupil center and the liquid crystal grating is equal to the preset optimal viewing distance; if so, move the light-transmitting area in the X-axis direction of the coordinate system of the liquid crystal grating, and the size of the moved light-transmitting area is the same as that of the light-transmitting area before movement; if not, adjust the size of the light-transmitting area in the X-axis direction of the coordinate system of the liquid crystal grating, and the adjusted light-transmitting area partially overlaps with the light-transmitting area before adjustment; Drive the liquid crystal grating so that the liquid crystal grating only transmits light at the position of the light-transmitting area corresponding to the real-time position.

2. The driving method according to claim 1, wherein, Determine the real-time position of the pupil center, specifically including: Real-time collect the facial image of the user, and determine the three-dimensional coordinates of the pupil center in the camera coordinate system based on the facial image.

3. The driving method according to claim 2, wherein Real-time collect the facial image of the user, and determine the three-dimensional coordinates of the pupil center in the camera coordinate system based on the facial image, specifically including: Use visible light cameras with different positions to respectively and real-time collect facial images; Respectively extract multiple first edge points of the iris in the facial images collected by each visible light camera at the same time, and match the first edge points at the same position in each facial image; Use the triangulation method to calculate the three-dimensional coordinates of each successfully matched first edge point in the camera coordinate system; Take the three-dimensional coordinates of the center of the mapping space of each first edge point in the camera coordinate system as the three-dimensional coordinates of the pupil center in the camera coordinate system.

4. The driving method according to claim 2, wherein Real-time collect the facial image of the user, and determine the three-dimensional coordinates of the pupil center in the camera coordinate system based on the facial image, specifically including: Use an infrared camera to real-time obtain the facial image of the user; Extract multiple first edge points of the iris in the facial image, and perform ellipse fitting on the multiple first edge points, and use the two-dimensional coordinates of the center of the fitted ellipse in the image coordinate system as the two-dimensional coordinates of the pupil center in the image coordinate system; Obtain multiple facial feature points in the facial image, and map the multiple facial feature points to the same positions on the pre-established three-dimensional human face model; Adjust the coordinate system of the three-dimensional human face model to coincide with the camera coordinate system; Take the mean or mode of the depth coordinates of multiple second edge points of the human eye in the three-dimensional human face model in the camera coordinate system as the depth coordinates of the pupil center in the camera coordinate system; Convert the two-dimensional coordinates of the pupil center in the image coordinate system into two-dimensional coordinates of the same dimension of the pupil center in the camera coordinate system, and the two-dimensional coordinates of the pupil center in the camera coordinate system and the depth coordinates of the pupil center in the camera coordinate system constitute the three-dimensional coordinates of the pupil center in the camera coordinate system.

5. The driving method according to claim 3, wherein, Establish a three-dimensional human face model, specifically including: Use a visible light camera to collect at least one facial image; Obtain multiple facial feature points of each facial image; Calculate the three-dimensional coordinates of the multiple facial feature points in the camera coordinate system using triangulation; Take one of the facial feature points as the origin of the coordinate system of the three-dimensional human face model to be established, and adjust the origin of the coordinate system of the three-dimensional human face model to coincide with the origin of the camera coordinate system, so that the three-dimensional coordinates of the multiple facial feature points in the camera coordinate system are converted into the three-dimensional coordinates in the coordinate system of the three-dimensional human face model to be established; Restore the three-dimensional face represented by the multiple facial feature points according to the three-dimensional coordinates of the multiple facial feature points in the coordinate system of the three-dimensional human face model to be established, and realize the establishment of the three-dimensional human face model.

6. The driving method according to any one of claims 2 to 5, wherein, Establish the correspondence between the position of the pupil center and the position of the light-transmitting area in the liquid crystal grating, specifically including: Taking the center of the liquid crystal grating as the origin of the coordinate system, the light-emitting direction of the liquid crystal grating as the positive direction of the Z axis, and the negative direction of the X axis of the camera coordinate system as the positive direction of the X axis, establish the coordinate system of the liquid crystal grating; Under the coordinate system of the liquid crystal grating, determine the light-transmitting areas at different positions in the liquid crystal grating corresponding to the pupil center at different positions.

7. The driving method according to claim 6, wherein, Judge whether the distance between the pupil center and the liquid crystal grating is equal to the preset optimal viewing distance, specifically including: Take the negative value of the x coordinate of the pupil center in the camera coordinate system determined in real time as the x coordinate of the pupil center in the coordinate system of the liquid crystal grating, and take the z coordinate of the pupil center in the camera coordinate system determined in real time as the z coordinate of the pupil center in the coordinate system of the liquid crystal grating; Judge whether the z coordinate of the pupil center in the coordinate system of the liquid crystal grating is equal to the preset optimal viewing distance.

8. The driving method according to any one of claims 1-5 and 7, wherein, Move the light-transmitting area in the X-axis direction of the coordinate system of the liquid crystal grating, specifically including: Detect the intersection coordinates of the extension line of the connection between the coordinate point of the pupil center and the origin in the coordinate system of the liquid crystal grating and the liquid crystal grating; Compare the x coordinate of the intersection coordinates with the coordinates of the same-side endpoints of each strip electrode in one period of the liquid crystal grating on the X axis. If the x coordinate of the intersection coordinates is greater than the endpoint coordinates of the (i-1)th strip electrode in one period and less than or equal to the endpoint coordinates of the ith strip electrode, then determine that the area where the ith to [(i + n / 2) - 1]th strip electrodes are located in each period is the light-transmitting area corresponding to the current pupil center, where n is the total number of strip electrodes in one period and n is an even number, and i is an integer greater than or equal to 2 and less than or equal to n / 2.

9. The driving method according to any one of claims 1-5 and 7, wherein, Adjust the size of the light-transmitting area in the X-axis direction of the coordinate system of the liquid crystal grating, specifically including: Calculate the position coordinates of each strip electrode on the X axis in a total of m periods, the coordinate range of the light-transmitting area corresponding to each left-eye pixel in the liquid crystal grating on the X axis, and the coordinate range of the light-transmitting area corresponding to each right-eye pixel in the liquid crystal grating on the X axis; Compare the position coordinates of the b-th strip electrode in the a-th period with the coordinate ranges of the light-transmissible regions corresponding to the left-eye pixels and the coordinate ranges of the light-transmissible regions corresponding to the right-eye pixels. If the position coordinates of the b-th strip electrode in the a-th period are simultaneously within the coordinate ranges of the light-transmissible regions corresponding to the left-eye pixels and the light-transmissible regions corresponding to the right-eye pixels, determine that the region where the b-th strip electrode is located in the a-th period is the light-transmissible region corresponding to the current pupil center. m is the total number of grating periods in the liquid crystal grating, a is an integer greater than or equal to 1 and less than or equal to m, and b is an integer greater than or equal to 1 and less than or equal to n.

10. A display device, wherein, It includes a backlight, a liquid crystal panel located on the light-emitting side of the backlight, and a liquid crystal grating located between the backlight and the liquid crystal panel. The liquid crystal grating is driven by the driving method according to any one of claims 1 to 9.

11. A display method of a display device as claimed in claim 10, wherein, It includes: In the two-dimensional display mode, control the liquid crystal grating to be completely light-transmissive. In the three-dimensional display mode, use the driving method according to any one of claims 1 to 9 to control the liquid crystal grating to form alternately arranged light-transmissive regions and light-blocking regions.

12. The display method according to claim 11, wherein, While adjusting the size of the light-transmissive region in the X-axis direction of the coordinate system of the liquid crystal grating, it further includes: Determine the total number of strip electrodes corresponding to the light-transmissive region, and adjust the backlight brightness emitted by the backlight based on the total number of strip electrodes. The backlight brightness has a negative correlation with the total number of strip electrodes.

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