Near-eye display device

Abstract

A near-eye display device includes a display, an optical structure, and a phase-adjustable structure. The optical structure is located on one side of the display and includes a lens structure and an optical film on the lens structure. The lens structure includes at least one lens. The phase-adjustable structure is located between the display and the optical structure, and image light emitted from the display passes through the phase-adjustable structure before entering the optical structure. The phase-adjustable structure includes a liquid crystal layer and an electrode layer located on at least one side of the liquid crystal layer. The electrode layer includes multiple electrodes, and the phase-adjustable structure includes at least two regions. Different voltages are applied to the electrodes in different regions to adjust the phase of light emitted from different regions to the optical structure. The phase-adjustable structure located between the display and the optical structure uses an electronically controlled method to compensate for phase retardation, which is beneficial for compensating for differences in local phase retardation caused by stress in the curved optical film within the optical structure.

Description

Technical Field

[0001] Embodiments of this disclosure relate to a near-eye display device. Background Technology

[0002] In optical systems used in near-eye display devices, such as head-mounted displays, the control of light polarization state is crucial to the system's performance. Phase retardation films, such as quarter-wave plates (QWPs) and linear polarizers (LPs), are typically used to ensure the polarization state of light along different optical paths. However, in optical systems employing folded optical path designs, the curvature of the phase retardation film on the curved surface of the lens can induce stress, leading to phase difference changes and affecting the final image display quality. Summary of the Invention

[0003] At least one embodiment of this disclosure provides a near-eye display device.

[0004] The near-eye display device provided in this disclosure includes a display, an optical structure, and a phase-adjustable structure. The optical structure is located on one side of the display and includes a lens structure and an optical film on the lens structure. The lens structure includes at least one lens. The phase-adjustable structure is located between the display and the optical structure, and image light emitted from the display passes through the phase-adjustable structure and then enters the optical structure. The phase-adjustable structure includes a liquid crystal layer and an electrode layer located on at least one side of the liquid crystal layer. The electrode layer includes multiple electrodes, and the phase-adjustable structure includes at least two regions. Different voltages are applied to the electrodes in different regions to adjust the phase of the light emitted from the different regions to the optical structure.

[0005] For example, according to an embodiment of this disclosure, the lens structure includes a first surface, and the optical film includes a first phase retardation film disposed on the first surface, wherein the first surface is a curved surface.

[0006] For example, according to an embodiment of this disclosure, the near-eye display device further includes: a first linear polarization layer located between the display and the phase-tunable structure to give polarization characteristics to light incident on the phase-tunable structure.

[0007] For example, according to an embodiment of this disclosure, the near-eye display device further includes: a second phase retardation film located on the side of the first linear polarization layer away from the display. The liquid crystal layer comprises liquid crystal molecules, and when the phase-tunable structure is not subjected to a voltage, the angle between the long axis of the liquid crystal molecules at each location in the liquid crystal layer and the fast axis of the second phase retardation film is the same first initial angle. The electrodes in the different regions are configured to apply different voltages to deflect the liquid crystal molecules in the different regions by different angles.

[0008] For example, according to an embodiment of this disclosure, the first initial included angle is 40 degrees to 50 degrees.

[0009] For example, according to an embodiment of this disclosure, the phase-adjustable structure is disposed on the surface of the second phase retardation film away from the first linear polarization layer, or the phase-adjustable structure is disposed between the second phase retardation film and the first linear polarization layer.

[0010] For example, according to an embodiment of this disclosure, the phase-tunable structure is disposed on the surface of the first linearly polarized layer; the liquid crystal layer includes liquid crystal molecules, and when the phase-tunable structure is not subjected to voltage, the angle between the long axis of the liquid crystal molecules at each position in the liquid crystal layer and the light transmission axis of the first linearly polarized layer is the same second initial angle; the electrode layer is configured to apply voltage so that at least a portion of the light emitted by the display after passing through the first linearly polarized layer and the phase-tunable structure is circularly polarized light.

[0011] For example, according to an embodiment of this disclosure, the display includes a substrate and a plurality of sub-pixels located on the substrate, wherein the ratio of the size of the electrode to the size of the sub-pixel is 0.8 to 1.2 in the same direction parallel to the main surface of the substrate.

[0012] For example, according to an embodiment of this disclosure, the near-eye display device further includes an eye tracker located on the side of the display facing the optical structure. The eye tracker is configured to determine a user's gaze point on the optical structure, and the phase-adjustable structure is configured to adjust the voltage applied to electrodes in a region corresponding to the position of the gaze point based on the position of the gaze point.

[0013] For example, according to an embodiment of this disclosure, the phase-adjustable structure includes a drive power supply electrically connected to the electrode layer, and the drive power supply is integrated into the driver of the display.

[0014] For example, according to an embodiment of this disclosure, the phase-adjustable structure completely covers the display surface of the display.

[0015] For example, according to an embodiment of this disclosure, the lens structure further includes a second surface located between the first surface and the display, and the optical film further includes a transflective film disposed on the second surface; the optical film further includes a reflective polarizing film and a second linear polarizing layer, both the reflective polarizing film and the second linear polarizing layer being located on the side of the transflective film away from the display, and the second linear polarizing layer being located on the side of the reflective polarizing film away from the transflective film. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure.

[0017] Figure 1 This is a schematic diagram of the partial stress distribution of the phase retardation film in an optical structure.

[0018] Figure 2 for Figure 1 The diagram shows the difference in phase delay at different locations of the phase delay film.

[0019] Figure 3 This is a partial cross-sectional structural diagram of a near-eye display device provided according to an embodiment of the present disclosure.

[0020] Figure 4 This is a schematic diagram of the partial stress distribution of the first phase retardation film in an optical structure.

[0021] Figure 5 for Figure 4 The diagram shows the difference in phase delay at different locations of the first phase delay film.

[0022] Figure 6A , Figure 6B as well as Figure 7 This is a partial cross-sectional structural diagram of a near-eye display device provided according to different examples of embodiments of the present disclosure.

[0023] Figure 8 This is a partial cross-sectional structural schematic diagram of a near-eye display device provided according to another example of an embodiment of the present disclosure.

[0024] Figure 9 This is a partial cross-sectional structural schematic diagram of a near-eye display device provided according to yet another example of an embodiment of the present disclosure. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Based on the described embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0026] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that an element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0027] The features such as "parallel," "perpendicular," and "identical" used in the embodiments of this disclosure include features in the strict sense of "parallel," "perpendicular," and "identical," as well as cases where "approximately parallel," "approximately perpendicular," and "approximately identical" include a certain degree of error. Taking into account measurement and errors associated with the measurement of a specific quantity (e.g., limitations of the measurement system), they represent the acceptable deviation range for a specific value as determined by a person skilled in the art. For example, "approximately" can mean within one or more standard deviations, or within 10% or 5% of said value. Unless otherwise specified in the following embodiments of this disclosure, the quantity of a component is implied to mean that the component can be one or more, or can be understood as at least one. "At least one" means one or more, and "more" means at least two.

[0028] A display device includes a display and an optical structure located on the light-emitting side of the display. The screen of the display is provided with a linear polarizer and a phase retardation film, such as a quarter-wave plate. Unpolarized light emitted from the screen becomes linearly polarized light after passing through the linear polarizer. The linearly polarized light is converted into circularly polarized light by the phase retardation film. This circularly polarized light is incident on the optical structure, which may include at least one lens and an optical film located on the at least one lens. The optical film may include a transmissive film, a phase retardation film, a reflective polarizing film, and a linearly polarizing film to form a pancake optical path. By modulating the polarization state of the light incident on the optical structure into a circularly polarized state, it is beneficial to achieve efficient propagation of light in the pancake optical path to maintain image quality.

[0029] In general display devices, the optical performance can be further improved by incorporating a fixed phase compensation film across the entire surface of the optical structure or in front of the screen. For example, a phase retardation film can be placed in a lens, such as a quarter-wave plate whose surface can be curved. In the optical structure, this compensation film can be placed on the quarter-wave plate, which helps reduce optical distortion caused by the lens curvature and improves overall image quality. Similarly, in front of the screen, a compensation film can be placed on a quarter-wave plate to adjust the phase of the emitted light, further optimizing the beam propagation characteristics after entering the optical structure and mitigating ghosting problems.

[0030] In their research, the inventors of this application discovered that although compensation films are placed in front of the screen or in the optical structure of a display device to adjust the polarization state of light, various problems still occur when light enters the optical structure. For example, when a phase retardation film is bent and attached to the curved surface of a lens, the curved surface of the lens causes the phase retardation film to deform at different positions due to different stretching or compression. This deformation generates stress inside the phase retardation film, which in turn causes the phase retardation film to have different phase retardation amounts at different positions.

[0031] Figure 1 This is a schematic diagram of the partial stress distribution of the phase retardation film in an optical structure. Figure 2 for Figure 1 The diagram shows the difference in phase delay at different locations of the phase delay film.

[0032] like Figure 1 and Figure 2 As shown, when a phase retardation film 02 is applied to the curved surface of a lens, the stress on the phase retardation film 02 varies at different locations, such as positions 021, 022, and 023. For example, the portion of the phase retardation film 02 located in the region of greater lens curvature may experience greater stress, resulting in a significant shift in phase retardation in that region; conversely, the portion of the phase retardation film 02 located in the region of lesser lens curvature experiences less stress, with almost no effect on phase retardation in that region. For instance, the stress on the phase retardation film 02 at positions 022 and 023 is greater than the stress at position 021.

[0033] like Figure 1 and Figure 2As shown, the phase retardation film 02 has a phase retardation reference line M. Before the curved application, the phase retardation of the phase retardation film 02 at each position is located on the reference line M. After the curved application, the phase retardation of the phase retardation film 02 at some positions, such as position 021, is still located on the reference line M, while the phase retardation at some positions, such as positions 022 and 023, is greater than or less than the phase retardation on the reference line M. As a result, the phase retardation of the phase retardation film shifts at some positions due to stress, which in turn causes ghosting in the image of the display device.

[0034] For example, Figure 1 The white areas, such as the three locations of position 021, are schematically shown. The phase delay of these areas is on the baseline M. The phase delay of other striped areas, such as positions 022 and 023, deviates from the phase delay on the baseline M. For example, the phase delay at these locations is greater than or less than the phase delay on the baseline M.

[0035] For example, Figure 1 The arrows at each location indicate the direction of the slow axis of the phase retardation film 02 at that location. For example, as shown... Figure 1 and Figure 2 As shown, the slow axis of the portion of the phase retardation film 02 at position 022 is rotated counterclockwise by a certain angle relative to the slow axis of the portion at position 021, and the phase delay at this position is less than the phase delay on the reference line M; the slow axis of the portion of the phase retardation film 02 at position 023 is rotated clockwise by a certain angle relative to the slow axis of the portion at position 021, and the phase delay at this position is greater than the phase delay on the reference line M.

[0036] This disclosure provides a near-eye display device, including a display, an optical structure, and a phase-tunable structure. The optical structure is located on one side of the display and includes a lens structure and an optical film on the lens structure. The lens structure includes at least one lens. The phase-tunable structure is located between the display and the optical structure, and image light emitted from the display passes through the phase-tunable structure and then enters the optical structure. The phase-tunable structure includes a liquid crystal layer and an electrode layer located on at least one side of the liquid crystal layer. The electrode layer includes multiple electrodes, and the phase-tunable structure includes at least two regions. Different voltages are applied to the electrodes in different regions to adjust the phase of light emitted from different regions to the optical structure.

[0037] The near-eye display device provided in this disclosure, by setting a phase-adjustable structure including a liquid crystal layer and an electrode layer between the display and the optical structure, and using an electronic control method to compensate for the phase delay, is beneficial to compensate for the difference in local phase delay caused by stress in the curved optical film in the optical structure, thereby improving the display effect.

[0038] The near-eye display device provided in this disclosure is described below with reference to the accompanying drawings.

[0039] Figure 3 This is a partial cross-sectional structural diagram of a near-eye display device provided according to an embodiment of the present disclosure.

[0040] like Figure 3 As shown, the near-eye display device includes a display 100, an optical structure 200, and a phase-adjustable structure 300. The optical structure 200 is located on one side of the display 100 and includes a lens structure 210 and an optical film 220 on the lens structure 210. The lens structure 210 includes at least one lens 211. The phase-adjustable structure 300 is located between the display 100 and the optical structure 200. Image light emitted from the display 100 passes through the phase-adjustable structure 300 and then enters the optical structure 200. The phase-adjustable structure 300 includes a liquid crystal layer 310 and an electrode layer 320 located on at least one side of the liquid crystal layer 310. The electrode layer 320 includes a plurality of electrodes 3200. The phase-adjustable structure 300 includes at least two regions 301. Different voltages are applied to the electrodes 3200 in different regions 301 to adjust the phase of the light emitted from different regions 301 to the optical structure 200.

[0041] The near-eye display device provided in this disclosure, by setting a phase-adjustable structure including a liquid crystal layer and an electrode layer between the display and the optical structure, and using an electronic control method to compensate for the phase delay, is beneficial to compensate for the difference in local phase delay caused by stress in the curved optical film in the optical structure, thereby improving the display effect.

[0042] For example, such as Figure 3 As shown, the optical structure 200 is located on the light-emitting side of the display 100. For example, the display 100 can be an organic light-emitting diode display or a liquid crystal display, etc., and this embodiment is not limited thereto. For example, in at least one direction perpendicular to the X direction, the size of the display 100 is smaller than the size of the optical structure 200. For example, in at least one direction perpendicular to the X direction, the size of the phase-adjustable structure 300 is not smaller than the size of the display surface of the display 100. For example, in at least one direction perpendicular to the X direction, the size of the phase-adjustable structure 300 is smaller than the size of the optical structure 200. For example, a gap is provided between the phase-adjustable structure 300 and the optical structure 200.

[0043] For example, such as Figure 3As shown, the phase-adjustable structure 300 may include two electrode layers 320, which are located on opposite sides of the liquid crystal layer 310. One electrode layer 320 includes a plurality of electrodes 3200 spaced apart, such as control electrodes, while the other electrode layer 320 is a full-surface electrode layer, such as a common electrode layer. For example, the control electrodes are located on the side of the liquid crystal layer 310 away from the display 100. However, this is not a limitation; for example, the control electrodes may be located between the liquid crystal layer 310 and the display 100, or the phase-adjustable structure 300 may include only one electrode layer 320, in which a plurality of electrodes 3200 are disposed.

[0044] The phase-tunable structure has multiple electrodes, which is beneficial to divide the phase-tunable structure into multiple independent regions. By applying different voltages to the electrodes in different regions, the local phase delay difference of the curved optical film in the optical structure can be compensated in a block-like manner.

[0045] For example, such as Figure 3 As shown, the phase-tunable structure 300 may include multiple regions 301, each region 301 being a three-dimensional region, including liquid crystal molecules 311 in the liquid crystal layer 310 and electrodes 3200 in the electrode layer 320, and each region 301 is provided with at least one electrode 3200. For example, at least one region 301 is provided with multiple electrodes 3200, and the electrodes 3200 in the same region 301 are subjected to the same voltage.

[0046] For example, such as Figure 3 As shown, the phase-tunable structure 300 further includes at least one cover plate 3001 to protect the electrode layer 320 and the liquid crystal layer 310. For example, the phase-tunable structure 300 includes two cover plates 3001, respectively located on the side of the two electrode layers 320 away from the liquid crystal layer 310.

[0047] In some examples, such as Figure 3 As shown, the lens structure 210 includes a first surface 2111, and the optical film 220 includes a first phase retardation film 221 disposed on the first surface 2111. The first surface 2111 is a curved surface. For example, the first phase retardation film 221 can be flexibly attached to the curved surface. In this embodiment of the present disclosure, no other film layer is disposed between the first phase retardation film and the first surface except for optical adhesive, but it is not limited to this. Other film layers can also be disposed between the first phase retardation film and the first surface, and the first phase retardation film can be attached to these other film layers. In this case, it can still be called a first phase retardation film disposed on the first surface.

[0048] like Figure 3As shown, the image light emitted from the display 100 passes through different regions 301 of the phase-tunable structure 300 and then enters different positions of the first phase retardation film 221. For example, these different positions can be positions where the first phase retardation film 221 has different phase retardation amounts. Based on the difference in phase retardation amount at different positions of the first phase retardation film 221 due to its curved surface, different voltages are applied to the electrodes 3200 in different regions 301 of the phase-tunable structure 300 corresponding to these different positions to adjust the deflection angle of the liquid crystal molecules 311 in different regions 301, thereby adjusting the phase retardation amount of the light emitted from different regions 301 of the phase-tunable structure 300 to the corresponding positions of the first phase retardation film 221.

[0049] For example, the phase delay at different locations in an optical structure can be detected using an optical feedback mechanism, such as when the phase delay is detected... Figure 1 The phase delay at different locations shown differs from the phase delay on the baseline, and this difference may be caused by the curvature of the first phase delay film.

[0050] Figure 4 This is a schematic diagram of the partial stress distribution of the first phase retardation film in an optical structure. Figure 5 for Figure 4 The diagram shows the difference in phase delay at different locations of the first phase delay film.

[0051] by Figure 4 The first phase retardation film 221 shown is... Figure 1 Taking the phase retardation film 02 attached to the same curved surface of the lens as an example, Figure 4 The positions 2211, 2212, and 2213 of the first phase retardation film 221 shown are respectively with Figure 1 The positions 021, 022 and 023 of the phase retardation film 02 shown are one-to-one corresponding positions.

[0052] refer to Figures 1 to 2 as well as Figures 4 to 5 The phase delay of the first phase delay film 221 at position 2211 is located on the reference line M. The difference between the phase delay of the first phase delay film 221 at position 2212 and the phase delay on the reference line M is smaller than the difference between the phase delay of the phase delay film 02 at position 022 and the phase delay on the reference line M. The difference between the phase delay of the first phase delay film 221 at position 2213 and the phase delay on the reference line M is smaller than the difference between the phase delay of the phase delay film 02 at position 023 and the phase delay on the reference line M.

[0053] For example, such as Figures 3 to 5As shown, image light emitted from the first region of the phase-tunable structure 300 is incident on position 2211 of the first phase retardation film 221, image light emitted from the second region of the phase-tunable structure 300 is incident on position 2212 of the first phase retardation film 221, and image light emitted from the third region of the phase-tunable structure 300 is incident on position 2213 of the first phase retardation film 221. Since the phase retardation of the first phase retardation film 221 at position 2211 is located on the reference line M, the electrode 3200 in the first region does not need to be subjected to voltage, so that the liquid crystal molecules 311 in the first region do not deflect, and the phase of the light rays passing through the first region in the image light emitted from the display 100 does not change. Figure 1 and Figure 3 The phase retardation difference at positions 022 and 023 of the phase retardation film is shown. The voltage applied to the electrodes 3200 in the second and third regions of the phase-adjustable structure 300 is adjusted to rotate the liquid crystal molecules 311 in the second and third regions by a certain angle, thereby changing the phase of the light rays passing through the second and third regions in the image light emitted from the display 100, so that it is consistent with the optically expected phase state. The difference between the phase retardation of the light rays with changed phase after incident on positions 2212 and 2213 of the first phase retardation film 221 and the phase retardation on the reference line is significantly reduced.

[0054] In the near-eye display device provided in this disclosure, a first phase retardation film 221 is disposed on the curved surface of a lens 211. By disposing of a phase-adjustable structure 300 including a liquid crystal layer 310 and an electrode layer 320 between the display 100 and the optical structure 200, different voltages can be applied to the electrodes 3200 in different regions 301 of the phase-adjustable structure 300 corresponding to different positions based on the difference in phase retardation at different positions of the first phase retardation film 221 caused by the curved surface. This adjusts the deflection angle of the liquid crystal molecules 311 in different regions 301, thereby adjusting the phase retardation of light emitted from different regions 301 of the phase-adjustable structure 300 to different positions of the first phase retardation film 221. This achieves precise compensation for the phase retardation shift in the first phase retardation film 221, reducing ghosting, polarization distortion, and other phenomena in the displayed image.

[0055] In some examples, such as Figure 3 As shown, the phase-adjustable structure 300 completely covers the display surface of the display 100.

[0056] By setting the phase-adjustable structure 300 to completely cover the display surface of the display 100, all image light emitted from the display 100 can pass through the phase-adjustable structure 300 before entering the optical structure 200, which facilitates the adjustment of the phase delay of the light rays incident on the optical structure at various positions on the display surface.

[0057] In some examples, such as Figure 3 As shown, the lens structure 210 further includes a second surface 2112, which is located between the first surface 2111 and the display 100. The optical film 220 also includes a transflective film 222 disposed on the second surface 2112. For example, the second surface 2112 can be a curved surface, and the transflective film 222 can be deposited on the second surface 2112. The optical film 220 also includes a reflective polarizing film 223 and a linear polarizing layer, such as a second linear polarizing layer 224. Both the reflective polarizing film 223 and the second linear polarizing layer 224 are located on the side of the transflective film 222 away from the display 100, and the second linear polarizing layer 224 is located on the side of the reflective polarizing film 223 away from the transflective film 222.

[0058] For example, such as Figure 3 As shown, the transflective membrane 222 is configured to transmit part of the light and reflect another part of the light. For example, the transflective membrane 222 may include at least one film layer, such as each film layer having a thickness of 10-200 nanometers. For example, the transflective membrane 222 may have a transmittance of 50% and a reflectance of 50%. For example, the transflective membrane 222 may have a transmittance of 60% and a reflectance of 40%. For example, the transflective membrane 222 may have a transmittance of 65% and a reflectance of 35%. For example, the transflective membrane 222 may also be referred to as a transflective membrane 222. The embodiments disclosed herein are not limited thereto, and the transmittance and reflectance of the transflective membrane 222 may be set according to product requirements.

[0059] For example, such as Figure 3 As shown, the reflective polarizing film 223 is configured to reflect linearly polarized light with one characteristic and transmit linearly polarized light with another characteristic.

[0060] For example, such as Figure 3 As shown, the function of the reflective polarizing film 223 is as follows: Within the plane of the film layer, there exists a transmission axis. The transmittance of the polarization component of incident light parallel to this transmission axis (such as s-polarized light) is greater than the transmittance of the polarization component perpendicular to this transmission axis (such as p-polarized light), and the reflectance of the polarization component parallel to this transmission axis (such as s-polarized light) is less than the reflectance of the polarization component perpendicular to this transmission axis (such as p-polarized light). For example, the reflective polarizing film 223 can also be called a polarizing beam splitter. For example, the transmittance of polarized light parallel to the transmission axis of the reflective polarizing film 223 is not less than 85%, and is not less than 90%, not less than 95%, and not less than 98%; the reflectance of polarized light perpendicular to the transmission axis of the reflective polarizing film 223 is not less than 85%, and is not less than 90%, not less than 95%, and not less than 98%.

[0061] For example, such as Figure 3As shown, the first phase retardation film 221 is configured to enable the transmitted light to switch between circularly polarized and linearly polarized states. For example, the first phase retardation film 221 can be a quarter-wave plate. For example, the material of the first phase retardation film 221 can include a liquid crystal polymer or polycarbonate. For example, the first phase retardation film 221 has the following characteristics: there is a direction with the lowest refractive index and a direction with the highest refractive index within the film plane, which are the fast axis and the slow axis, respectively; the phase of polarized light parallel to the slow axis after passing through the first phase retardation film 221 is delayed by 1 / 4 wavelength compared to the phase of polarized light parallel to the fast axis after passing through the first phase retardation film 221.

[0062] For example, such as Figure 3 As shown, the angle between the slow axis of the first phase retardation film 221 and the transmission axis of the reflective polarization film 223 is 45 degrees.

[0063] For example, such as Figure 3 As shown, the transmission axis of the second linear polarization layer 224 coincides with the transmission axis of the reflective polarization film 223. The second linear polarization layer 224 can be used to further filter other stray light, allowing only polarized light (such as s-polarized light) that passes through the second linear polarization layer 224 to enter the human eye.

[0064] For example, such as Figure 3 As shown, the transflective film 222 and the reflective polarizing film 223 serve as two reflective surfaces, providing an ultra-short focal length folded optical path (Pancake). The arrangement of the transflective film 222 and the reflective polarizing film 223 enables the folding of light, so that the focal length of the optical system, which would have increased due to the arrangement of the reflective polarizing film 223 and the transflective film 222, is folded away, for example, by the two reflections. This greatly reduces the space required between the human eye and the optical system, making the optical system smaller and thinner.

[0065] Figure 3The lens structure 210 schematically illustrates a lens 211. The first surface 2111 and the second surface 2112 are two surfaces of the same lens 211. For example, a transflective coating 222 is located on the side of the lens 211 facing the display 100, as on the second surface 2112. A first phase retardation film 221, a reflective polarizing film 223, and a second linear polarizing layer 224 are located on the other side of the lens 211, as on the first surface 2111. For instance, the reflective polarizing film 223 can be optically bonded to the surface of the first phase retardation film 221, and the second linear polarizing layer 224 can be optically bonded to the surface of the reflective polarizing film 223. However, this is not a limitation. The lens structure 210 may also include multiple lenses 211. The first surface 2111 and the second surface 2112 may be different surfaces of the same lens 211, or they may be surfaces of different lenses 211. The first phase retardation film, the reflective polarizing film, and the second linear polarizing layer may be located on the same lens surface or on different lens surfaces.

[0066] In some examples, such as Figure 3 As shown, the display 100 includes a substrate 110 and a plurality of sub-pixels 120 located on the substrate 110. In the same direction parallel to the main surface of the substrate 110, the ratio of the size of the electrode 3200 to the size of the sub-pixel 120 is 0.8 to 1.2.

[0067] For example, such as Figure 3 As shown, the main surface of the substrate 110 is the surface of the substrate 110 perpendicular to the X direction. The same direction parallel to the main surface of the substrate 110 can be any direction perpendicular to the X direction, such as the Y direction. For example, in the same direction parallel to the main surface of the substrate 110, the ratio of the size of the electrode 3200 to the size of the sub-pixel 120 can be 0.8, or 1.2, or 0.85 to 1, or 0.9 to 1.05, or 0.95 to 1.02, etc. This embodiment does not list specific values ​​for the ratio of the size of the electrode 3200 to the size of the sub-pixel 120; the ratio can be any value between 0.8 and 1.2.

[0068] The near-eye display device provided in this disclosure sets the size ratio of sub-pixels and electrodes in the same direction to 0.8 to 1.2, making the size of electrodes and sub-pixels comparable. This is beneficial to improving the partition control accuracy of the phase-tunable structure. For example, the phase-tunable structure has pixel-level control accuracy, so as to achieve accurate compensation for the phase delay of at least a local area of ​​the first phase delay film in the optical structure, and reduce ghosting, polarization distortion and other phenomena in the displayed image.

[0069] Compared to near-eye display devices that typically have a fixed phase compensation film on the entire surface of the optical structure or in front of the display screen, the phase-adjustable structure provided in the near-eye display device of this disclosure can accurately compensate for the phase delay of the first phase delay film at different positions, and even adjust it in real time, so as to better compensate for the non-uniformity of the local phase delay in the first phase delay film caused by stretching or compression during the bending process.

[0070] For example, such as Figure 3 As shown, the multiple sub-pixels 120 may include multiple red sub-pixels, multiple blue sub-pixels, and multiple green sub-pixels. However, they are not limited to these; for example, the multiple sub-pixels may also include multiple white sub-pixels, etc.

[0071] For example, such as Figure 3 As shown, the multiple electrodes 3200 can have the same arrangement as the multiple sub-pixels 120, such as the multiple sub-pixels 120 being arranged in an array along the Y direction and in a direction perpendicular to the XY plane, and the multiple electrodes 3200 being arranged in an array along the Y direction and in a direction perpendicular to the XY plane.

[0072] For example, such as Figure 3 As shown, multiple electrodes 3200 are arranged in a one-to-one correspondence with multiple sub-pixels 120. For example, the orthographic projection of each electrode 3200 on the substrate 110 can overlap with the orthographic projection of its corresponding sub-pixel 120 on the substrate 110.

[0073] For example, such as Figure 3 As shown, the orthographic projection of each electrode 3200 onto the substrate 110 can be rectangular, with a side length of 3 to 14 micrometers.

[0074] Figure 6A , Figure 6B as well as Figure 7 This is a partial cross-sectional structural diagram of a near-eye display device provided according to different examples of embodiments of the present disclosure.

[0075] Figures 6A to 7 The display 100 and optical structure 200 shown are Figure 3 The display 100 and optical structure 200 shown have the same features, which will not be described again here.

[0076] In some examples, such as Figures 6A to 7 As shown, the near-eye display device also includes a first linear polarization layer 410 located between the display 100 and the phase-tunable structure 300, so that the light incident on the phase-tunable structure 300 has polarization characteristics.

[0077] For example, such as Figure 6A As shown, the transmission axis of the first linear polarization layer 410 is orthogonal to the transmission axis of the second linear polarization layer 224. For example, the first linear polarization layer 410 can be attached to the screen surface of the display 100.

[0078] In some examples, such as Figure 6A As shown, the near-eye display device also includes a second phase retardation film 420 located on the side of the first linear polarization layer 410 away from the display 100.

[0079] For example, such as Figure 6A As shown, the second phase retardation film 420 can be a quarter-wave plate. For example, the slow axis of the second phase retardation film 420 is orthogonal to the slow axis of the first phase retardation film 221. For example, if the image light emitted from the screen of the display 100 is unpolarized light, the angle between the slow axis of the second phase retardation film 420 and the transmission axis of the first linear polarization layer 410 is 45 degrees, so that the light emitted after the unpolarized light passes through the first linear polarization layer 410 and the second phase retardation film 420 is circularly polarized light. For example, the second phase retardation film 420 can be attached to the surface of the first linear polarization layer 410.

[0080] In some examples, such as Figure 6A As shown, the liquid crystal layer 310 includes liquid crystal molecules 311. When no voltage is applied to the phase-tunable structure 300, the angle between the long axis of the liquid crystal molecules 311 at each position in the liquid crystal layer 310 and the fast axis of the second phase retardation film 420 is the same first initial angle. The electrodes 3200 in different regions 301 are configured to apply different voltages to deflect the liquid crystal molecules 311 in different regions 301 by different angles. For example, the long axis of all liquid crystal molecules 311 in the liquid crystal layer 310 has the same first initial angle with the fast axis of the second phase retardation film 420.

[0081] In the initial state, such as when no voltage is applied, the liquid crystal molecules 311 in each region 301 of the liquid crystal layer 310 have the same first initial angle with the fast axis of the second phase retardation film 420. The deflection angle of the liquid crystal molecules 311 in different regions 301 of the liquid crystal layer 310 corresponding to different positions of the first phase retardation film 221 is adjusted according to the phase retardation difference at different positions of the first phase retardation film 221. This adjusts the phase retardation of the light emitted from the display 100 after passing through different regions 301 of the liquid crystal layer 310. As a result, the light incident on at least two different positions of the first phase retardation film 221 after passing through the liquid crystal layer 310 has different phase retardation, thereby compensating for the phase retardation difference of the first phase retardation film.

[0082] In some examples, such as Figure 6A As shown, the first initial included angle is 40 degrees to 50 degrees. For example, the first initial included angle is 45 degrees. For example, the first initial included angle is 40 degrees. For example, the first initial included angle is 50 degrees. For example, the first initial included angle is 42 degrees to 48 degrees. For example, the first initial included angle is 43 degrees to 46 degrees. For example, the first initial included angle is 41 degrees to 47 degrees. For example, the first initial included angle is 44 degrees to 49 degrees. This embodiment of the disclosure will not list all specific angles of the first initial included angle; the first initial included angle can be any angle within the range of 40 degrees to 50 degrees.

[0083] By setting the first initial included angle within the range of 40 to 50 degrees, the phase compensation angle of the phase-adjustable structure 300 can be quickly adjusted.

[0084] By setting the initial arrangement direction of the liquid crystal molecules to form a first initial angle with the fast axis of the first phase retardation film, such as 45 degrees, the alignment direction of the liquid crystal molecules is precisely aligned with the axial direction of the first phase retardation film. This alignment can effectively adjust the phase retardation of light and avoid poor compensation or unexpected phase shifts. In this application, the initial arrangement direction of the liquid crystal molecules refers to the arrangement direction of the liquid crystal layer when no voltage is applied.

[0085] For the phase-tunable structure 300, the corresponding example is... Figure 1 The liquid crystal molecules 311 in region 301 at position 021 of the phase retardation film shown have no phase retardation difference at this position because the first phase retardation film 221 has essentially no difference in phase retardation. Therefore, the liquid crystal molecules 311 in region 301 corresponding to this position do not deflect and still have the first initial angle. The angle between the long axis of the liquid crystal molecules 311 in region 301 corresponding to other positions of the first phase retardation film 221, such as position 022 or position 023, and the fast axis of the second phase retardation film is different from the first initial angle. For example, the difference between this angle and the first initial angle is not greater than 50 degrees, so as to realize the rapid adjustment of the phase compensation angle by the phase-adjustable structure.

[0086] In some examples, such as Figure 6A As shown, the phase-tunable structure 300 is disposed on the surface of the second phase retardation film 420 away from the first linear polarization layer 410. For example, the phase-tunable structure 300 is attached to the surface of the second phase retardation film 420, such as a cover plate of the phase-tunable structure 300 being attached to the surface of the second phase retardation film 420. For example, the phase-tunable structure 300 modulates the phase of circularly polarized light emitted from the second phase retardation film 420, and the modulated light is incident on the optical structure 200.

[0087] In some examples, such as Figure 6B As shown, the phase-tunable structure 300 is disposed between the second phase retardation film 420 and the first linear polarization layer 410. For example, one side cover plate of the phase-tunable structure 300 can be attached to the surface of the first linear polarization layer 410, and the second phase retardation film 420 is attached to the other side cover plate of the phase-tunable structure 300. For example, the phase-tunable structure 300 modulates the phase of the linearly polarized light emitted from the first linear polarization layer 410. The modulated light is incident on the second phase retardation film 420, which further delays the phase of the modulated light before it is incident on the optical structure 200.

[0088] The near-eye display device provided in this disclosure integrates the first linear polarization layer 410 and the second phase retardation film 420 on the display 100, while also integrating the phase-adjustable structure 300 on the second phase retardation film 420, which is beneficial for achieving a compact design and reducing the size of the near-eye display device.

[0089] In some examples, such as Figure 7 As shown, the phase-tunable structure 300 is disposed on the surface of the first linear polarization layer 410; the liquid crystal layer 310 includes liquid crystal molecules 311. When the phase-tunable structure 300 is not subjected to voltage, the angle between the long axis of the liquid crystal molecules 311 at each position in the liquid crystal layer 310 and the light transmission axis of the first linear polarization layer 410 is the same second initial angle. The electrode layer 320 is configured to apply voltage so that at least part of the light emitted by the display 100 after passing through the first linear polarization layer 410 and the phase-tunable structure 300 is circularly polarized light.

[0090] By setting the initial arrangement direction of each liquid crystal molecule to the same angle as the light transmission axis of the first linear polarization layer, the arrangement direction of the liquid crystal molecules is precisely aligned with the light transmission axis of the first linear polarization layer. This alignment can effectively adjust the phase retardation of light and avoid poor compensation effect or unexpected phase shift.

[0091] Compared to Figure 6A and Figure 6B The near-eye display device shown, Figure 7 In the near-eye display device shown, the phase-adjustable structure 300 replaces the second phase retardation film 420. It also needs to compensate for the phase retardation difference of the first phase retardation film 221 at different positions. For example, linearly polarized light emitted from the first linear polarization layer 410, after phase adjustment by the phase-adjustable structure 300, emits polarized light that has been matched to the phase retardation difference at each position of the first phase retardation film 221. The near-eye display device using the phase-adjustable structure 300 instead of the second phase retardation film 420 can further reduce its size.

[0092] Figure 8 This is a partial cross-sectional structural schematic diagram of a near-eye display device provided according to another example of an embodiment of the present disclosure.

[0093] Figure 8 The near-eye display device is schematically shown to include a second phase retardation film 420, but is not limited thereto; the near-eye display device in this example may also not include the second phase retardation film 420. Figure 8 The structure other than the power supply 330 and driver 150 shown is similar to Figure 7 The structures shown have the same characteristics, which will not be repeated here.

[0094] In some examples, such as Figure 8 As shown, the phase-adjustable structure 300 includes a driving power supply 330, which is electrically connected to the electrode layer 320 and is integrated into the driver 150 of the display 100. For example, the driver 150 of the display 100 is configured to drive a plurality of sub-pixels 120 to emit light.

[0095] Compared to designs that typically incorporate a phase-fixed compensation film within the optical structure, the near-eye display device disclosed herein places the phase-adjustable structure on the display side. This not only facilitates integrating the driving power supply for the phase-adjustable structure into the display's driver but also simplifies the design of the optical structure.

[0096] Of course, the embodiments disclosed herein are not limited to this, and the drive power supply 330 in the phase-adjustable structure 300 can also be set separately.

[0097] Figure 9 This is a partial cross-sectional structural schematic diagram of a near-eye display device provided according to yet another example of an embodiment of the present disclosure.

[0098] Figure 9 The near-eye display device is schematically shown to include a second phase retardation film 420, but is not limited thereto. The near-eye display device in this example may also not include the second phase retardation film 420. In the near-eye display device in this example, the driving power supply 330 of the phase adjustable structure 300 may be integrated into the driver 150 of the display 100. Figure 9The structure of the eye tracker 500 shown is different from that of the eye tracker 500. Figure 7 The structures shown have the same characteristics, which will not be repeated here.

[0099] In some examples, such as Figure 9 As shown, the near-eye display device also includes an eye tracker 500 located on the side of the display 100 facing the optical structure 200. The eye tracker 500 is configured to determine the user's gaze point on the optical structure 200, and the phase-adjustable structure 300 is configured to adjust the voltage applied to the electrode 3200 in the region 301 corresponding to the gaze point position according to the gaze point position. For example, the eye tracker 500 is configured to determine the position of the user's gaze point on the first phase retardation film 221. For example, the eye tracker 500 may be located between the optical structure 200 and the eyeball 600.

[0100] Figure 3 as well as Figures 6A to 8 In the near-eye display device shown, the phase-adjustable structure 300 can adjust the difference in phase delay at different positions of the first phase delay film 221 with the eyebox fixed, such as when the human eye is looking straight ahead. The eyebox can refer to the planar or three-dimensional area where the user's eyes are located and the image displayed by the display 100 can be clearly seen.

[0101] The near-eye display device provided in this disclosure combines an eye tracker 500 with a phase-adjustable structure 300 for feedback-based adaptive adjustment. Based on the gaze point of the eye 600 on the optical structure 200, such as the position of the gaze point on the first phase retardation film 221 and the phase retardation difference at that position, the voltage applied to the electrode 3200 in the corresponding region of the phase-adjustable structure 300 is adjusted in real time to adjust the deflection direction of the liquid crystal molecules 311. This achieves real-time adjustment of the phase retardation difference according to the eye movement process, which helps to reduce ghosting.

[0102] For example, the near-eye display device also includes a controller, and the eye tracker 500 and the phase-adjustable structure 300 are both electrically connected to the controller.

[0103] For example, eye trackers can employ gaze tracking technology, such as 2D gaze tracking or 3D gaze tracking. For instance, 2D tracking technology, represented by the pupil-corneal reflection method, uses a vector formed by the pupil center and a bright spot on the cornea to represent the gaze direction; 3D tracking technology uses dual or multiple cameras to obtain the coordinates of various reference points in 3D space for gaze tracking. For example, an eye tracker may include an image acquisition unit and an image processing unit. For example, in one embodiment of this disclosure, the image acquisition unit is configured to acquire images of both irises, and the image processing unit is configured to process the acquired iris images to build a 3D model of both irises, and locate the gaze focus of both eyes based on the 3D model. For example, in another embodiment of this disclosure, the image acquisition unit is configured to acquire a spot of red light reflected from the user's eyes, and the image processing unit is configured to perform gaze estimation on the spot in the acquired infrared image to determine the gaze focus. For example, in another example of the embodiments of this disclosure, the image acquisition unit is configured to acquire infrared light reflected from the eyeballs of both eyes to form an eye image, and the image processing unit acquires the eye image and preset eye parameter information to determine the gaze focus information of the two eyes. For example, the image acquisition unit may include a camera, which may be a color camera or an infrared camera. For example, the eye tracker may include multiple cameras to illuminate the eyeballs of both eyes from different angles. For example, the image processing unit may employ high-speed computing modules such as Digital Signal Processing (DSP) or Field Programmable Gate Array (FPGA) for image processing.

[0104] For example, the eye tracker transmits the gaze point information to the controller. The controller adjusts the input electrical signal to the electrodes in the region corresponding to the gaze point in the phase-adjustable structure according to the gaze point position, so as to adjust the deflection direction of the liquid crystal molecules in that region and realize real-time compensation for the difference in phase delay at the gaze point position.

[0105] For example, the aforementioned controller can refer to a controller that implements control functions in hardware. That is, without considering cost, anyone skilled in the art can build the corresponding hardware circuit to implement the control functions. For example, this hardware circuit includes conventional very large-scale integrated circuits (VLSI) or gate arrays, as well as existing semiconductors such as logic chips, transistors, or other discrete components. For example, the controller can also be implemented using programmable hardware devices, such as field-programmable gate arrays, programmable array logic, programmable logic devices, etc., and this embodiment does not impose any limitations on this.

[0106] For example, the aforementioned controller can also refer to a controller whose control functions are implemented using software algorithms, so that it can be executed by various types of processors. For instance, considering the current level of hardware technology, the controller can be a module implemented using software algorithms.

[0107] The following points need to be explained:

[0108] (1) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure, and other structures can be referred to the general design.

[0109] (2) Where there is no conflict, features of the same embodiment and different embodiments of this disclosure may be combined with each other.

[0110] The above description is merely an exemplary embodiment of this disclosure and is not intended to limit the scope of protection of this disclosure, which is determined by the appended claims.

Claims

1. A near-eye display device, comprising: monitor; An optical structure is located on one side of the display, wherein the optical structure includes a lens structure and an optical film located on the lens structure, and the lens structure includes at least one lens; A phase-adjustable structure is located between the display and the optical structure. Image light emitted from the display passes through the phase-adjustable structure and then enters the optical structure. The phase-tunable structure includes a liquid crystal layer and an electrode layer located on at least one side of the liquid crystal layer. The electrode layer includes multiple electrodes. The phase-tunable structure includes at least two regions, and different voltages are applied to the electrodes in different regions to adjust the phase of the light emitted from the different regions to the optical structure.

2. The near-eye display apparatus of claim 1, wherein, The lens structure includes a first surface, and the optical film includes a first phase retardation film disposed on the first surface, wherein the first surface is a curved surface.

3. The near-eye display device according to claim 2, further comprising: A first linear polarizing layer is located between the display and the phase-tunable structure to give polarization characteristics to light incident on the phase-tunable structure.

4. The near-eye display device according to claim 3, further comprising: The second phase retardation film is located on the side of the first linear polarization layer away from the display; The liquid crystal layer includes liquid crystal molecules. When no voltage is applied to the phase-tunable structure, the angle between the long axis of the liquid crystal molecules at each position in the liquid crystal layer and the fast axis of the second phase retardation film is the same first initial angle. The electrodes in the different regions are configured to apply different voltages to deflect the liquid crystal molecules in the different regions by different angles.

5. The near-eye display apparatus of claim 4, wherein, The first initial included angle is 40 degrees to 50 degrees.

6. The near-eye display device according to claim 4, wherein, The phase-adjustable structure is disposed on the surface of the second phase retardation film away from the first linear polarization layer, or the phase-adjustable structure is disposed between the second phase retardation film and the first linear polarization layer.

7. The near-eye display apparatus of claim 3, wherein, The phase-tunable structure is disposed on the surface of the first linear polarization layer; The liquid crystal layer includes liquid crystal molecules. When the phase-tunable structure is not subjected to voltage, the angle between the long axis of the liquid crystal molecules at each position in the liquid crystal layer and the light transmission axis of the first linear polarization layer is the same second initial angle. The electrode layer is configured to apply voltage so that at least a portion of the light emitted by the display after passing through the first linear polarization layer and the phase-tunable structure is circularly polarized light.

8. The near-eye display apparatus of any one of claims 1-7, wherein, The display includes a substrate and a plurality of sub-pixels located on the substrate. In the same direction parallel to the main surface of the substrate, the ratio of the size of the electrode to the size of the sub-pixel is 0.8 to 1.

2.

9. The near-eye display device according to any one of claims 1-7, further comprising: An eye tracker is located on the side of the display facing the optical structure. The eye tracker is configured to determine the user's gaze point on the optical structure, and the phase-adjustable structure is configured to adjust the voltage applied to electrodes in the region corresponding to the gaze point based on the position of the gaze point.

10. The near-eye display apparatus of any one of claims 1-7, wherein, The phase-adjustable structure includes a driving power supply, which is electrically connected to the electrode layer and is integrated into the driver of the display.

11. The near-eye display device of any one of claims 1-7, wherein, The phase-adjustable structure completely covers the display surface of the monitor.

12. The near-eye display apparatus of claim 2, wherein, The lens structure further includes a second surface located between the first surface and the display, and the optical film further includes a transmissive and reflective film disposed on the second surface; The optical film further includes a reflective polarizing film and a second linear polarizing layer. Both the reflective polarizing film and the second linear polarizing layer are located on the side of the reflective film away from the display, and the second linear polarizing layer is located on the side of the reflective polarizing film away from the reflective film.

Images