Display device and control method thereof

Abstract

The application discloses a display device and a control method thereof. The display device comprises a light source, a spatial light modulator, a field lens and a grating assembly arranged in sequence. The light source is used for sequentially emitting coherent backlight beams of multiple colors. The spatial light modulator is used for phase modulation and / or amplitude modulation on the backlight beams. The display device further comprises at least one refractive device, which is located on the side of the field lens away from the spatial light modulator and is used for deflecting the light rays by a first preset angle in a first working mode. The first preset angle is greater than zero. By adopting the above technical means, the light rays can be deflected by the first preset angle in the first working mode by arranging the refractive device, so that the visual angle of the display device is improved, and the user demand is met.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a display device and its control method. Background Technology

[0002] To meet the demand for stereoscopic displays in electronic devices, electronic devices with 3D holographic display capabilities have become a major development direction in the display field. Electronic devices can achieve 3D holographic display functionality by integrating a holographic display system.

[0003] When electronic devices with 3D holographic display capabilities display images, the light signals are modulated in phase and amplitude by spatial light modulators (SLMs), and then the left-eye and right-eye images are typically formed through the diffraction function of a liquid crystal grating. Improving the display effect has become an urgent problem to be solved. Summary of the Invention

[0004] This invention provides a display device and its control method to improve the viewing angle of the display device and meet user needs.

[0005] In a first aspect, embodiments of the present invention provide a display device, comprising a light source, a spatial light modulator, a field lens, and a grating assembly arranged sequentially.

[0006] The light source is used to sequentially emit coherent backlight beams of multiple colors;

[0007] The spatial light modulator is used to perform phase modulation and / or amplitude modulation on the backlight beam;

[0008] The display device further includes at least one refractive device, which is located on the side of the field lens away from the spatial light modulator, and is used to deflect the light as a whole by a first preset angle in the first working mode, wherein the first preset angle is greater than zero.

[0009] Secondly, embodiments of the present invention also provide a control method for a display device, comprising:

[0010] Obtain the target's angle at its location;

[0011] When the target angle is greater than the threshold angle, at least one refractive device is controlled to operate in the first working mode to deflect the light as a whole by a first preset angle, wherein the first preset angle is greater than zero.

[0012] In the display device provided in this embodiment of the invention, at least one refractive device is disposed on the side of the field lens away from the spatial light modulator. The refractive device can deflect the light as a whole by a first preset angle when the user moves to an oblique viewing angle, thereby providing an additional deflection amount on the basis of the deflection of the light by the grating assembly, so as to increase the deflection angle of the light, improve the viewing angle of the display device, and meet the user's needs. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a display device provided in an embodiment of the present invention;

[0014] Figure 2 This is a schematic diagram of another display device provided in an embodiment of the present invention;

[0015] Figure 3 For example Figure 1 A schematic diagram of the display device in its second operating mode;

[0016] Figure 4 This is a schematic diagram of another display device provided in an embodiment of the present invention;

[0017] Figure 5 A top view schematic diagram of a first liquid crystal grating provided in an embodiment of the present invention;

[0018] Figure 6 For along Figure 5 A cross-sectional schematic diagram of AA' in the middle;

[0019] Figure 7 A top view schematic diagram of a first refractive device provided in an embodiment of the present invention;

[0020] Figure 8 For along Figure 7 Cross-sectional schematic diagram of BB';

[0021] Figure 9 A top view schematic diagram of a second liquid crystal grating provided in an embodiment of the present invention;

[0022] Figure 10 This is a schematic diagram of the structure of another display device provided in an embodiment of the present invention;

[0023] Figure 11 This is a schematic diagram of the structure of another display device provided in an embodiment of the present invention;

[0024] Figure 12 This is a schematic diagram of the structure of another display device provided in an embodiment of the present invention;

[0025] Figure 13 This is a schematic diagram showing the connection of the third electrode in a first deflection device according to an embodiment of the present invention;

[0026] Figure 14 A top view schematic diagram of a second refractive device provided in an embodiment of the present invention;

[0027] Figure 15 For along Figure 14 A cross-sectional view of CC' in the middle;

[0028] Figure 16 For along Figure 14 Another cross-sectional view of CC';

[0029] Figure 17 For along Figure 14 Another cross-sectional schematic diagram of CC';

[0030] Figure 18 For along Figure 14 Another cross-sectional schematic diagram of CC';

[0031] Figure 19 For along Figure 14 Another cross-sectional schematic diagram of CC';

[0032] Figure 20 A top view schematic diagram of a third refractive device provided in an embodiment of the present invention;

[0033] Figure 21 For along Figure 20 A cross-sectional schematic diagram of DD' in the middle;

[0034] Figure 22 A flowchart illustrating a control method for a display device provided in an embodiment of the present invention;

[0035] Figure 23 A flowchart illustrating another control method for a display device provided in an embodiment of the present invention;

[0036] Figure 24 This is a flowchart illustrating another control method for a display device provided in an embodiment of the present invention. Detailed Implementation

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0038] Figure 1 This is a schematic diagram of the structure of a display device provided in an embodiment of the present invention, such as... Figure 1As shown, the display device includes a light source 10, a spatial light modulator 20, a field lens 30, a grating assembly 40, and at least one refractive device 50 arranged sequentially. Figure 1 A refractive device 50 is illustrated exemplarily. The light source 10 is used to sequentially emit coherent backlight beams of multiple colors. The sequentially emitted backlight beams of multiple colors are emitted in a sequential order. Exemplarily, the light source 10 may employ a backlight module, which may emit red, green, and blue backlight beams in a time-division manner to achieve the display of the screen on the display device.

[0039] Spatial light modulator 20 is used to phase modulate and / or amplitude modulate the backlight beam. Field lens 30 is used to converge the light to the viewing window at the human eye position, so that the human eye can see the image displayed by the display device. That is, the field lens 30 can direct the light modulated by spatial light modulator 20 onto grating assembly 40, thereby forming left-eye and right-eye images. Refractive device 50 is located on the side of field lens 30 away from spatial light modulator 20. Refractive device 50 is used to deflect the light as a whole by a first preset angle in the first working mode, the first preset angle being greater than zero. As a comparison, in the prior art, because the grating assembly 40 has a limited deflection angle for the light, the diffraction efficiency of the light is low at a large viewing angle, which is difficult to meet the user's viewing needs. In other words, in the prior art, when the user is in the center viewing position of the display device, both the left and right eyes can form relatively clear images. However, when the user moves from the center viewing position of the display device to an oblique viewing angle without changing the position of the display device, the grating assembly 40 cannot deflect the light at a large angle, resulting in a poor user experience. In this embodiment of the invention, by setting at least one refractive device 50 on the side of the field mirror 30 away from the spatial light modulator 20, the light can be deflected by a first preset angle when the user moves to an oblique viewing angle. Thus, even if the user is far from the center viewing position of the display device, the light can still be deflected to the human eye by the refractive device 50, thereby improving the viewing angle of the display device and meeting the user's needs.

[0040] Continue to refer to Figure 1 The refractive element 50 can be located on the side of the grating assembly 40 away from the field lens 30. In other embodiments, the refractive element 50 may also have other placement positions.

[0041] Figure 2 This is a schematic diagram of another display device provided in an embodiment of the present invention, such as... Figure 2 As shown, the refractive device 50 can also be located between the grating assembly 40 and the field lens 30.

[0042] refer to Figure 1 and Figure 2The number of refractive devices 50 is one. In other embodiments, the number of refractive devices 50 can be multiple. At least two of the multiple refractive devices 50 can deflect light at the same or similar azimuth angles. Thus, by adding at least two deflections with the same or similar azimuth angles, a larger angle of light deflection can be achieved.

[0043] In the display device provided in this embodiment of the invention, at least one refractive device 50 is provided on the side of the field lens 30 away from the spatial light modulator 20. The refractive device 50 can deflect the light as a whole by a first preset angle when the user moves to an oblique viewing angle, thereby providing an additional deflection amount on the basis of the deflection of the light by the grating assembly 40, so as to increase the deflection angle of the light, improve the viewing angle of the display device, and meet the user's needs.

[0044] Figure 3 For example Figure 1 The diagram shown illustrates the display device in its second operating mode. (Refer to...) Figure 1 and Figure 3 The refractive device 50 is also used in the second operating mode to deflect the light as a whole by a second preset angle or not to deflect the light at all, where the second preset angle is smaller than the first preset angle. The refractive device 50 deflects the light at a greater angle in the first operating mode than in the second operating mode, thus providing a greater additional deflection amount in the first operating mode than in the second operating mode, based on the deflection of the light by the grating assembly 40. Alternatively, the refractive device 50 may not provide an additional deflection amount in the second operating mode.

[0045] For example, in the first operating mode, the user is in a viewing position far from the center of the display device (left eye a and right eye b are in a viewing position far from the center of the display device), which has a large tilt angle. In the second operating mode, the user is in a viewing position closer to the center of the display device (left eye a and right eye b are in a viewing position closer to the center of the display device), which has a small tilt angle.

[0046] Figure 4 This is a schematic diagram of another display device provided in an embodiment of the present invention, with reference to... Figure 4 The display device includes two spatial light modulators 20, namely a phase spatial light modulator 201 and an amplitude spatial light modulator 202. The phase spatial light modulator 201 is used to modulate the phase of the backlight beam, and the amplitude spatial light modulator 202 is used to modulate the amplitude of the backlight beam. In other embodiments, the display device may include only one of the phase spatial light modulator 201 and the amplitude spatial light modulator 202. The grating assembly 40 includes a plurality of liquid crystal gratings 401. Figure 4The diagram illustrates three liquid crystal gratings 401. In other embodiments, the grating assembly 40 may include other numbers of liquid crystal gratings 401. The three liquid crystal gratings 401 are a first liquid crystal grating 41, a second liquid crystal grating 42, and a third liquid crystal grating 43.

[0047] Figure 5 This is a top view schematic diagram of a first liquid crystal grating provided in an embodiment of the present invention. Figure 6 For along Figure 5 A cross-sectional schematic diagram of AA' is shown in the reference diagram. Figure 5 and Figure 6 The liquid crystal grating 401 includes a first substrate 4011, a first electrode 4012, a first liquid crystal layer 4013, a second electrode 4014, and a second substrate 4015 arranged sequentially. The first liquid crystal layer 4013 is located between the first substrate 4011 and the second substrate 4015, the first electrode 4012 is located between the first substrate 4011 and the first liquid crystal layer 4013, and the second electrode 4014 is located between the first liquid crystal layer 4013 and the second substrate 4015.

[0048] For example, a first dielectric layer 4016 may be included between the first substrate 4011 and the first electrode 4012, and a second dielectric layer 4017 may be included between the second electrode 4014 and the second substrate 4015. By providing the first dielectric layer 4016 and the second dielectric layer 4017, the liquid crystal grating 401 can be protected from damage by the external environment. On the other hand, the charge between the electrodes can be effectively isolated to prevent charge leakage and arcing, thus ensuring that the liquid crystal grating 401 can work normally.

[0049] For example, the first liquid crystal layer 4013 includes liquid crystal molecules, the first electrode 4012 can be multiple and independently arranged, and the second electrode 4014 can be a full-surface electrode. There is a voltage difference between the first electrode 4012 and the second electrode 4014, so that the longitudinal electric field formed by the first electrode 4012 and the second electrode 4014 can drive the liquid crystal molecules in the first liquid crystal layer 4013 to rotate, thereby refracting the light incident on the liquid crystal grating 401.

[0050] Figure 7 This is a top view schematic diagram of a first refractive device provided in an embodiment of the present invention. Figure 8 For along Figure 7 A cross-sectional diagram of BB', as shown below. Figure 7 and Figure 8As shown, the refractive device 50 includes a third substrate 501, a third electrode 502, a second liquid crystal layer 503, a fourth electrode 504, and a fourth substrate 505 arranged sequentially. The second liquid crystal layer 503 is located between the third substrate 501 and the fourth substrate 505. The third electrode 502 is located between the third substrate 501 and the second liquid crystal layer 503. The fourth electrode 504 is located between the second liquid crystal layer 503 and the fourth substrate 505.

[0051] Exemplarily, the second liquid crystal layer 503 includes liquid crystal molecules, and the third electrode 502 can be multiple independently disposed electrodes or a single, continuous electrode. The fourth electrode 504 can also be a single, continuous electrode. A voltage difference exists between the third electrode 502 and the fourth electrode 504, so that the longitudinal electric field formed by the third electrode 502 and the fourth electrode 504 can drive the liquid crystal molecules in the second liquid crystal layer 503 to rotate, thereby refracting the light incident on the refractive device 50. Unlike the liquid crystal grating 401, which uses diffraction to deflect light, the refractive device 50 uses refraction to deflect light. (Reference) Figures 4-8 The liquid crystal grating 401 includes a first liquid crystal grating 41, in which a plurality of first electrodes 4012 are spaced apart from each other along a first direction X. The spaced-apart first electrodes 4012 are arranged along the first direction X. Along the first direction X, adjacent first electrodes 4012 are spaced apart by a certain distance and do not physically contact each other. At least one refractive device 50 includes a first refractive device 51, in which a plurality of third electrodes 502 are spaced apart from each other along a second direction Y. The spaced-apart third electrodes 502 are arranged along the second direction Y. Along the second direction Y, adjacent third electrodes 502 are spaced apart by a certain distance and do not physically contact each other. The angle between the first direction X and the second direction Y is less than or equal to 10°. In this embodiment of the invention, the refractive device 50 is implemented using a liquid crystal cell. The arrangement direction of the first electrode 4012 in the first liquid crystal grating 41 is the same as or similar to the arrangement direction of the third electrode 502 in the first refractive device 51. Therefore, based on the light deflection by the first liquid crystal grating 41, the first refractive device 51 provides an additional deflection, achieving the superposition of light deflection along the first direction X. Light deflection along the first direction X can be, for example, light deflection in the horizontal direction (0-degree azimuth angle).

[0052] For example, such as Figures 5-8 As shown, the angle between the first direction X and the second direction Y is ω, where ω is greater than or equal to 1° and less than or equal to 10°. 1°≤ω≤10°. There is a small angle between the first direction X and the second direction Y, and the first direction X and the second direction Y are not parallel, thereby reducing the moiré pattern formed between the first liquid crystal grating 41 and the first refractive device 51 and improving the display quality of the display device.

[0053] Figure 9This is a top view schematic diagram of a second liquid crystal grating provided in an embodiment of the present invention. Figure 10 This is a schematic diagram of the structure of another display device provided in an embodiment of the present invention, with reference to... Figure 6 , Figure 9 and Figure 10 As shown, the plurality of liquid crystal gratings 401 include a first liquid crystal grating 41 and a second liquid crystal grating 42. The first liquid crystal grating 41 is located between the field lens 30 and the second liquid crystal grating 42. In the second liquid crystal grating 42, a plurality of first electrodes 4012 are spaced apart from each other along a third direction Z. A plurality of first electrodes 410, spaced apart from each other, are arranged along a third direction Z. Along the third direction Z, adjacent first electrodes 4012 are spaced a certain distance apart and do not physically contact each other. The angle between the first direction X and the third direction Z is 45°.

[0054] like Figure 10 As shown, the display device also includes a first waveplate 61. The first waveplate 61 can be understood as a light rotator, capable of changing the polarization direction of light. The first waveplate 61 is located between the first liquid crystal grating 41 and the second liquid crystal grating 42, and is used to rotate the polarization direction of the light incident on the first waveplate 61 so that it is parallel to the third direction Z before exiting. Since the long axis direction of the liquid crystal molecules in the second liquid crystal grating 42 needs to be adapted to the polarization direction of the light, by placing the first waveplate 61 between the first liquid crystal grating 41 and the second liquid crystal grating 42, the first waveplate 61 can rotate the light so that its polarization direction is consistent with the third direction Z. That is, the first waveplate 61 rotates the light so that its polarization direction is consistent with the direction of the deflected light from the second liquid crystal grating 42, thereby adapting the long axis direction of the liquid crystal molecules in the second liquid crystal grating 42 to the polarization direction of the light projected onto the second liquid crystal grating 42. The first refractive device 51 is located between the first liquid crystal grating 41 and the first wave plate 61. The first refractive device 51 and the first liquid crystal grating 41 are arranged adjacent to each other with the same or similar direction of deflection of light, so that there is no need to set up a separate and additional optical rotation element for the first refractive device 51. This arrangement is simple and the display device has a compact structure.

[0055] Figure 11 This is a schematic diagram of the structure of another display device provided in an embodiment of the present invention, as shown below. Figure 11 As shown, the first refractive device 51 is located between the field lens 30 and the first liquid crystal grating 41. In one embodiment, the backlight beam emitted from the light source 10 is linearly polarized light, and if the backlight beam is X-polarized in the first direction, then a waveplate is not required between the first liquid crystal grating 41 and the field lens 30. By placing the first refractive device 51 and the first liquid crystal grating 41 adjacent to each other with the same or similar deflection directions, it is not necessary to separately and additionally provide a light-rotating element for the first refractive device 51. This arrangement is simple and the display device structure is compact.

[0056] Figure 12 This is a schematic diagram of the structure of another display device provided in an embodiment of the present invention, as shown below. Figure 12 As shown, the display device also includes a second waveplate 62, which is located between the field lens 30 and the first refractive device 51. The second waveplate 62 is used to rotate the polarization direction of the light incident on the second waveplate 62 so that it is parallel to the first direction X before being emitted. Since the backlight beam emitted from the light source 10 is linearly polarized light, and if the backlight beam is not polarized in the first direction X, a second waveplate 62 needs to be placed between the first liquid crystal grating 41 and the field lens 30, that is, between the field lens 30 and the first refractive device 51. In this way, the second waveplate 62 can rotate the polarization direction of the light incident on the second waveplate 62 so that it is parallel to the first direction X before being emitted to the first deflector 51, thus adapting to the long axis direction of the liquid crystal molecules in the first deflector 51 and the polarization direction of the light projected onto the first deflector 51. Since the first refractive device 51 and the first liquid crystal grating 41 have similar directions of light refraction, and the first refractive device 51 and the first liquid crystal grating 41 are arranged adjacent to each other, there is no need to set up a separate and additional light-rotating element for the first liquid crystal grating 41. This arrangement is simple and the display device has a compact structure.

[0057] Continue to refer to Figure 6 and Figure 8 The first liquid crystal grating 41 includes a plurality of first grating units 411 arranged along a first direction X. In the first liquid crystal grating 41, the plurality of first grating units 411 are repeatedly arranged along the first direction X. Each first grating unit 411 includes a plurality of first electrodes 4012, and the length of the first grating unit 411 along the first direction X is a first length K1. The first refractive device 51 includes a plurality of first deflection units 511 arranged along a second direction Y. In the first refractive device 51, the plurality of first deflection units 511 are repeatedly arranged along the second direction Y. Each first deflection unit 511 includes a plurality of third electrodes 502, and the length of the first deflection unit 511 along the second direction Y is a second length K2. The second length K2 is greater than the first length K1. It is understood that the number of first electrodes 4012 in each first grating unit 411 of the first liquid crystal grating 41 changes with different frames. Therefore, the first length K1 changes with different frames. Regardless of how the frames change, the number of third electrodes 502 in each first deflection unit 511 of the first refractive device 51 remains unchanged. Therefore, the second length K2 can be a fixed value. In this embodiment of the invention, regardless of how the first length K1 changes with different frames, it is always less than the second length K2. Thus, the first refractive device 51, which utilizes the principle of refraction, has a larger periodic unit length than the first grating unit 411, which utilizes the principle of diffraction. Herein, a frame is the period of time during which light of one color shines on one eye of the observer.

[0058] For example, along the second direction Y, the distance between the centers of two adjacent third electrodes 502 is greater than or equal to 5 μm and less than or equal to 10 μm.

[0059] Continue to refer to Figure 6 and Figure 8 The grating assembly 40 includes multiple liquid crystal gratings 401. Each liquid crystal grating 401 includes a first substrate 4011, a first electrode 4012, a first liquid crystal layer 4013, a second electrode 4014, and a second substrate 4015 arranged sequentially. The vertical distance between the first substrate 4011 and the second substrate 4015 is D1. The refractive device 50 includes a third substrate 501, a third electrode 502, a second liquid crystal layer 503, a fourth electrode 504, and a fourth substrate 505 arranged sequentially. The vertical distance between the third substrate 502 and the fourth substrate 505 is D2. D1 < D2, meaning that the liquid crystal cell thickness of the refractive device 50 is greater than the liquid crystal cell thickness of the liquid crystal grating 401. Thus, the liquid crystal grating 401 uses diffraction to deflect light, and the refractive device 50 uses refraction to deflect light. Therefore, based on the light deflection by the liquid crystal grating 401, the refractive device 50 provides an additional deflection, achieving a superposition of light deflection.

[0060] Continue to refer to Figure 8 The D2 value satisfies 50μm≤D2≤100μm, which enables the refraction of light by the refractive device 50. If D2 is less than 50μm, the liquid crystal cell thickness of the refractive device 50 is too small to achieve a sufficiently large angle of light deflection. If D2 is greater than 100μm, the liquid crystal cell thickness of the refractive device 50 is too large, providing an excessively large, unused light deflection angle. Increasing the cell thickness leads to an increase in the thickness of the display device and a decrease in the liquid crystal response rate. In this embodiment of the invention, setting 50μm≤D2≤100μm reduces the cell thickness and increases the liquid crystal response rate while providing a suitable angle of light deflection.

[0061] Continue to refer to Figure 4 The grating assembly 40 includes multiple liquid crystal gratings 401. The frequency at which the liquid crystal gratings 401 switch their deflection angle is H1, and the frequency at which the refractive device 50 switches its deflection angle is H2. H1 > H2, meaning that the frequency at which the refractive device 50 switches its deflection angle is less than the frequency at which the liquid crystal gratings 401 switch their deflection angle. This allows for a lower switching voltage to be provided to the refractive device 50 than the frequency of the liquid crystal gratings 401, reducing the difficulty of controlling the refractive device 50.

[0062] Understandably, the number and / or voltage of the first electrodes 4012 within each first grating unit 411 of the first liquid crystal grating 41 changes with different frames. The number of voltage changes on the first electrode 4012 per second is the frequency H1. The number of third electrodes 502 within each first deflection unit 511 of the first refractive device 51 remains constant, and the voltage of the third electrode 502 within each first deflection unit 511 of the first refractive device 51 changes only every few frames. There is usually no change between two adjacent frames. The number of voltage changes on the third electrode 502 per second is the frequency H2.

[0063] Optionally, H2 satisfies 0.5Hz ≤ H2 ≤ 10Hz. If H2 is less than 0.5Hz, the frequency at which the refractive device 50 switches its deflection angle is too low, making it unable to keep up with the movement of the human eye. If H2 is greater than 10Hz, the frequency at which the refractive device 50 switches its deflection angle is too high, providing an excessively large and unused switching frequency. Increasing the frequency at which the refractive device 50 switches its deflection angle increases the difficulty of controlling the refractive device 50. In this embodiment of the invention, setting 0.5Hz ≤ H2 ≤ 10Hz reduces the difficulty of controlling the refractive device 50 while providing a suitable switching frequency.

[0064] Figure 13 This is a schematic diagram of the connection of the third electrode in a first deflection device according to an embodiment of the present invention, as shown below. Figure 13 As shown, the first refractive device 51 includes a plurality of first deflection units 511 arranged along the second direction Y, and each first deflection unit 511 includes a plurality of third electrodes 502. The third electrodes 502 in at least two first deflection units 511 are electrically connected, thus simplifying the control method.

[0065] It should be noted that continued reference is necessary. Figure 6 For the liquid crystal grating 401, the number of first electrodes 4012 in each first grating unit 411 needs to be changed according to the changes in the display screen, that is, the number of first electrodes 4012 in each first grating unit 411 varies from 4 to several hundred, thereby changing the diffraction angle. Therefore, in the liquid crystal grating 401, each first electrode 4012 is controlled individually. However, for the refractive device 50, it is not necessary to change the number of third electrodes 502 in each first refractive unit 511 according to the changes in the display screen, that is, the number of third electrodes 502 in each first deflection unit 511 is the same. Therefore, the third electrodes 502 with the same ordinal number in each first deflection unit 511 can be connected to the same source signal line. Only 10-20 sets of source signal lines are needed to control the third electrode 502, thus simplifying the control method.

[0066] Figure 14This is a top view schematic diagram of a second refractive device provided in an embodiment of the present invention. Figure 15 For along Figure 14 A cross-sectional view of CC'. Figure 16 For along Figure 14 Another cross-sectional view of CC', as shown below. Figures 14-16 As shown, the refractive device 50 includes a third substrate 501, a third electrode 502, a second liquid crystal layer 503, a fourth electrode 504, and a fourth substrate 505 arranged sequentially. At least one refractive device 50 includes a second refractive device 52, which further includes a prism topography defining layer 520 located between the fourth electrode 504 and the fourth substrate 505, and includes a plurality of prism topography defining units 5201 arranged along the fourth direction W. Figure 15 and Figure 16 The prism topography defining units 5201 shown are arranged along a fourth direction W, and the fourth direction W is the same as the second direction Y. It is understood that in other embodiments, the fourth direction W may also be different from the second direction Y.

[0067] For example, the material of the prism shape definition unit 5201 can be an imprinting resin or similar material. The refractive index of the resin is around 1.5.

[0068] refer to Figure 15 Along the fourth direction W, the thickness of the prism topography defining unit 5201 gradually decreases. Alternatively, refer to... Figure 16 Along the fourth direction W, the thickness of the prism topography defining unit 5201 gradually increases, wherein the thickness of the prism topography defining unit 5201 is the thickness of the prism topography defining unit 5201 along the plane perpendicular to the fourth substrate 505.

[0069] It should be noted that if the refractive index of the resin used in the prism morphology defining unit 5201 is closer to the e-ray refractive index, the liquid crystal molecules will not be deflected when no voltage is applied to the third electrode 502 and the fourth electrode 503. If the refractive index of the resin used in the prism morphology defining unit 5201 is closer to the o-ray refractive index, the liquid crystal molecules will be deflected when no voltage is applied to the third electrode 502 and the fourth electrode 503. In one embodiment, when no voltage is applied to the third electrode 502 and the fourth electrode 503, the refractive index of the liquid crystal molecules is different from that of the resin, and thus the light incident on the second refractive device 52 will be deflected; when a voltage is applied to the third electrode 502 and the fourth electrode 503, the refractive index of the liquid crystal molecules is the same as that of the resin, and thus the light incident on the second refractive device 52 will not be deflected. In another embodiment, when a voltage is applied to the third electrode 502 and the fourth electrode 503, the refractive index of the liquid crystal molecules differs from that of the resin, causing light incident on the second refractive device 52 to be deflected. Conversely, when no voltage is applied to the third electrode 502 and the fourth electrode 503, the refractive index of the liquid crystal is the same as that of the resin, and therefore the light incident on the second refractive device 52 is not deflected. Typically, a larger voltage is applied to the third electrode 502 and the fourth electrode 503 to make all the liquid crystal molecules stand upright, thus causing the second refractive device 52 to deflect the incident light.

[0070] Figure 17 For along Figure 14 Another cross-sectional schematic diagram of CC', such as Figure 17 As shown, multiple prism morphology defining units 5201 share the same third electrode 502, and multiple prism morphology defining units 5201 share the same fourth electrode 503. That is, both the third electrode 502 and the fourth electrode 503 are full-surface electrodes. Thus, the fabrication process of the second refractive device 52 is simple, and the control method is also simple.

[0071] Continue to refer to Figure 15 and Figure 16 Multiple third electrodes 502 are spaced apart along the fourth direction W, meaning that adjacent third electrodes 502 are spaced a certain distance apart and do not make physical contact. Multiple prism topography defining units 5021 share the same fourth electrode. When a voltage is applied to the third electrode 502 and the fourth electrode 503, the electric field strength is greater at positions where the third electrode 502 and the fourth electrode 503 are closer together, resulting in a larger rotation angle for the liquid crystal molecules. Since the rotation angle of liquid crystal molecules at different positions is different in the same horizontal direction, a relatively large voltage is usually applied to the electrodes to make the liquid crystal molecules at all positions stand upright, thereby achieving the deflection of light.

[0072] The two adjacent third electrodes 502 are spaced apart by a certain distance. That is to say, the third electrode 502 is an independently driven pixel electrode. A small voltage can be applied to the pixel electrode that is close to the third electrode 502 and the fourth electrode 503, and a large voltage can be applied to the pixel electrode that is far from the third electrode 502 and the fourth electrode 503. This makes the standing angle of the liquid crystal molecules at each position the same. The liquid crystal layer under the applied voltage can be regarded as a film layer with a uniform refractive index, thereby improving the accuracy of the second refractive device 52 in deflecting light.

[0073] Figure 18 For along Figure 14 Another cross-sectional schematic diagram of CC', such as Figure 18 As shown, the display device includes a first display area 71 and a second display area 72 arranged along a fourth direction W. For example, the first display area 71 may be the left display area of ​​the display device, and the second display area 72 may be the right display area of ​​the display device.

[0074] The prism topography defining unit 5201 includes a first prism topography defining unit 521 and a second prism topography defining unit 522. The first prism topography defining unit 521 is located in the first display area 71, and the second prism topography defining unit 522 is located in the second display area 72. Along the fourth direction W, the thickness of the first prism topography defining unit 521 gradually decreases, while the thickness of the second prism topography defining unit 522 gradually increases or decreases. In other words, along the fourth direction W, the thickness change of the first prism topography defining unit 521 in the first display area 71 is opposite to the thickness change of the second prism topography defining unit 522 in the second display area 72. Thus, the deflecting device 50 in the first display area 71 deflects light to the left, and the deflecting device 50 in the second display area 72 deflects light to the right. Or, Figure 19 For along Figure 14 Another cross-sectional schematic diagram of CC', such as Figure 19 As shown, along the fourth direction W, the thickness of the first prism shape defining unit 521 gradually increases, while the thickness of the second prism shape defining unit 522 gradually decreases. This enables the deflection device 50 in the first display area 71 to deflect light to the left and the deflection device 50 in the second display area 72 to deflect light to the right, and also allows for diverse settings of the display device.

[0075] Figure 20 This is a top view schematic diagram of a third refractive device provided in an embodiment of the present invention. Figure 21 For along Figure 20 A cross-sectional schematic diagram of DD', as shown below. Figure 20 and Figure 21As shown, at least one refractive device 50 further includes a third refractive device 53, in which a plurality of third electrodes 502 are spaced apart from each other along a fifth direction V. The plurality of third electrodes 502, spaced apart from each other, are arranged along the fifth direction V. Along the fifth direction V, adjacent third electrodes 502 are spaced a certain distance apart and do not physically contact each other. The angle between the first direction X and the fifth direction V is 90°.

[0076] Continue to refer to Figures 5-7 The grating assembly 40 includes a plurality of liquid crystal gratings 401. Each liquid crystal grating 401 includes a first substrate 4011, a first electrode 4012, a first liquid crystal layer 4013, a second electrode 4014, and a second substrate 4015 arranged sequentially. Each liquid crystal grating 401 includes a first liquid crystal grating 41, in which a plurality of first electrodes 4012 extend along a fifth direction. The refractive device 50 includes a third substrate 501, a third electrode 502, a second liquid crystal layer 503, a fourth electrode 504, and a fourth substrate 505 arranged sequentially. At least one refractive device 50 includes a first refractive device 51, in which a third electrode extends along a sixth direction. The angle θ between the fifth and sixth directions is less than or equal to 10°. It should be noted that the arrangement direction of the electrodes is perpendicular to the extension direction. In other embodiments, they may not be perpendicular. The arrangement direction of the first electrode 4012 in the first liquid crystal grating 41 is the same as or similar to the arrangement direction of the third electrode 502 in the first refractive device 51. Thus, based on the deflection of light by the first liquid crystal grating 41, the first refractive device 51 provides an additional deflection amount, thereby achieving the superposition of light deflection.

[0077] Continue to refer to Figure 1 At least one refractive element 50 is located on the side of the grating assembly 40 away from the field mirror 30. The number of refractive elements 50 can be one or more. At least two of the multiple refractive elements 50 can deflect light rays with the same or similar azimuth angles. Thus, by adding at least two deflections with the same or similar azimuth angles, a larger angle of light deflection can be achieved.

[0078] In summary, the display device provided in this embodiment of the invention has at least one refractive device 50 disposed on the side of the field lens 30 away from the spatial light modulator 20. The refractive device 50 can deflect the light as a whole by a first preset angle when the user moves to an oblique viewing angle, thereby providing an additional deflection amount on the basis of the deflection of the light by the grating assembly 40, so as to increase the deflection angle of the light, improve the viewing angle of the display device, and meet the user's needs.

[0079] Based on the same inventive concept, embodiments of the present invention also provide a control method for a display device, which is implemented based on the display device described in the above embodiments. Figure 22This is a flowchart illustrating a control method for a display device provided in an embodiment of the present invention, as shown below. Figure 22 As shown, the control method includes:

[0080] S101, Obtain the target angle at the target's location.

[0081] Specifically, the target angle can be understood as at least one of the centers of the user's left or right pupils. This means that when the user moves towards the right eye, due to the greater right-side deflection angle, the target angle is the angle between the center of the right pupil and the center of the right pupil when the user is in the center of the display device. Similarly, when the user moves towards the left eye, due to the greater left-side deflection angle, the target angle is the angle between the center of the left pupil and the center of the left pupil when the user is in the center of the display device.

[0082] S102. When the target angle is greater than the threshold angle, control at least one refractive device to work in the first working mode to deflect the light as a whole by a first preset angle, the first preset angle being greater than zero.

[0083] Specifically, when the target angle exceeds a threshold angle, it indicates that the user has moved from the center viewing position of the display device to an oblique viewing angle. Since the grating assembly cannot deflect light at a large angle, the user experience will be poor. In this embodiment of the invention, when the user is at an oblique viewing angle, the refractive device deflects the light as a whole by a first preset angle. Thus, even if the user is far from the center viewing position of the display device, the light can still be deflected to the human eye by the refractive device, thereby improving the viewing angle of the display device and meeting the user's needs.

[0084] For example, in the first working mode, the user is in a viewing position far from the center of the display device (the left and right eyes are in a viewing position far from the center of the display device), at which time there is a large tilt angle.

[0085] It is understandable that when a user is facing the display device, the deflection angle of the liquid crystal grating switching between the eyes is approximately 2.48°. When this angle exceeds 2.48°, the liquid crystal grating alone cannot effectively deflect the light. For example, the threshold angle can be 4°. When the target angle is greater than the threshold angle, a refractive device is used to deflect the light towards the human eye, thereby improving the viewing angle of the display device and meeting the user's needs.

[0086] S103. When the target angle is less than or equal to the threshold angle, control the refractive device to work in the second working mode, deflect the light as a whole by a second preset angle or not deflect the light, wherein the second preset angle is less than the first preset angle.

[0087] Specifically, when the target angle is less than or equal to the threshold angle, the refractive device is in the second operating mode. The refractive device can deflect the light entirely by a second preset angle or not deflect the light at all, where the second preset angle is less than the first preset angle. In the first operating mode, the refractive device deflects the light at a greater angle than in the second operating mode. Therefore, in addition to the deflection of the light by the grating assembly, the refractive device provides a greater additional deflection in the first operating mode than in the second operating mode. Alternatively, the refractive device may not provide any additional deflection in the second operating mode.

[0088] For example, in the second working mode, the user is in a viewing position close to the center of the display device (both the left and right eyes are in a viewing position close to the center of the display device), at which time there is a small tilt angle.

[0089] The control method for a display device provided in this invention obtains the target angle at the location of the target. When the target angle is greater than a threshold angle, at least one refractive device is controlled to operate in a first operating mode, deflecting the light as a whole by a first preset angle. This allows the light to be deflected to the user's eye even when the user is far from the center viewing position of the display device, thereby improving the viewing angle of the display device and meeting user needs. Furthermore, when the target angle is less than or equal to the threshold angle, the refractive device is controlled to operate in a second operating mode. In the second operating mode, since the user is closer to the center viewing position of the display device, the refractive device can deflect the light as a whole by a second preset angle or not deflect the light at all.

[0090] Figure 23 This is a flowchart illustrating another control method for a display device provided in an embodiment of the present invention. Figure 23 Based on the above embodiments, the operation of controlling at least one refractive device to operate in a first working mode and deflecting the light beam by a first preset angle when the target angle is greater than a threshold angle is further described, such as... Figure 23 As shown, the control method includes:

[0091] S201. Obtain the target angle at the location of the target.

[0092] S202. When the target angle is greater than the threshold angle, obtain the first preset angle based on the target angle.

[0093] Specifically, a first preset angle is obtained based on the deflection angle of the user's eye, so that the refractive device deflects the light at the first preset angle to meet the user's viewing needs.

[0094] S203. Control at least one refractive device to operate in the first working mode, so as to deflect the light as a whole according to the first preset angle.

[0095] Specifically, based on the obtained first preset angle, the refractive device is controlled to work in the first working mode, so that the light is deflected as a whole according to the first preset angle. This control is highly precise and can meet the user's viewing needs.

[0096] S204. When the target angle is less than or equal to the threshold angle, control the refractive device to work in the second working mode, deflect the light as a whole by a second preset angle or not deflect the light, wherein the second preset angle is less than the first preset angle.

[0097] The control method for the display device provided in this embodiment of the invention obtains a first preset angle based on the target angle when the target angle is greater than a threshold angle, and then controls the refractive device to deflect the light as a whole by the first preset angle, thus achieving high control precision.

[0098] Figure 24 This is a flowchart illustrating another control method for a display device provided in an embodiment of the present invention. Figure 24 Based on the above embodiments, the operation after controlling at least one refractive device to operate in the first working mode and deflecting the light as a whole by a first preset angle when the target angle is greater than the threshold angle is further described, such as... Figure 24 As shown, the control method includes:

[0099] S301, Obtain the target angle at the target's location.

[0100] S302. When the target angle is greater than the threshold angle, control at least one refractive device to work in the first working mode to deflect the light as a whole by a first preset angle, the first preset angle being greater than zero.

[0101] S303. Obtain the grating deflection angle of the grating assembly based on the first preset angle and the target deflection angle.

[0102] Specifically, the target deflection angle can be understood as the angle at which the user's eye deflects the light. The deflection angle of the grating component can be calculated by subtracting a first preset angle from the target deflection angle, thus enabling the grating component to deflect according to the grating deflection angle.

[0103] S304. Keep the current first preset angle unchanged until the target angle changes.

[0104] Specifically, if the target angle does not change, it means the user's viewing angle remains unchanged. Therefore, if the user's viewing angle does not change, the current first preset angle can be kept constant to ensure that the refractive device deflects the light by the first preset angle before it reaches the user's eye. When the user's viewing angle changes, it means the user's position has moved. In this case, the first preset angle can be obtained based on the target angle, or the light can be left undeflected to change the overall deflection angle of the light.

[0105] S305. When the target angle is less than or equal to the threshold angle, control the refractive device to work in the second working mode, and deflect the light as a whole by a second preset angle, the second preset angle being less than the first preset angle.

[0106] The control method for a display device provided in this invention, when the target angle is greater than a threshold angle, controls at least one refractive device to operate in a first working mode. After deflecting the light as a whole by a first preset angle, the grating deflection angle of the grating assembly is obtained based on the first preset angle and the target deflection angle, so that the grating assembly deflects the light according to the grating deflection angle. Furthermore, the current first preset angle is kept unchanged until the target angle changes; that is, if the user's viewing angle does not change, the current first preset angle can be kept constant to ensure that the light is incident on the user's eye after the refractive device has deflected the light as a whole by the first preset angle. When the user's viewing angle changes, the first preset angle can be obtained based on the target angle to change the overall deflection angle of the light, thus ensuring the stability and reliability of the display device's operation.

[0107] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A display device, characterized in that, It includes a light source, a spatial light modulator, a field lens, and a grating assembly arranged in sequence; The light source is used to sequentially emit coherent backlight beams of multiple colors; The spatial light modulator is used to perform phase modulation and / or amplitude modulation on the backlight beam; The display device further includes at least one refractive device, which is located on the side of the field lens away from the spatial light modulator, and is used to deflect the light as a whole by a first preset angle in the first working mode, wherein the first preset angle is greater than zero. The grating assembly includes a plurality of liquid crystal gratings; the liquid crystal grating includes a first liquid crystal grating, in which a plurality of first electrodes are spaced apart from each other along a first direction; the at least one refractive device includes a first refractive device, in which a plurality of third electrodes are spaced apart from each other along a second direction; the angle between the first direction and the second direction is greater than or equal to 1°, and the angle between the first direction and the second direction is less than or equal to 10°.

2. The display device according to claim 1, characterized in that, The refractive device is also used in the second working mode to deflect the light as a whole by a second preset angle or not to deflect the light, wherein the second preset angle is smaller than the first preset angle.

3. The display device according to claim 1, characterized in that, The liquid crystal grating includes a first substrate, a first electrode, a first liquid crystal layer, a second electrode, and a second substrate arranged sequentially. The refractive device includes a third substrate, a third electrode, a second liquid crystal layer, a fourth electrode, and a fourth substrate arranged sequentially.

4. The display device according to claim 3, characterized in that, The liquid crystal grating includes a second liquid crystal grating, and the first liquid crystal grating is located between the field lens and the second liquid crystal grating; In the second liquid crystal grating, a plurality of the first electrodes are spaced apart from each other along a third direction, and the angle between the first direction and the third direction is 45°; The display device further includes a first wave plate, which is located between the first liquid crystal grating and the second liquid crystal grating, and is used to rotate the polarization direction of the light incident on the first wave plate to be parallel to the third direction before it is emitted. The first refractive device is located between the first liquid crystal grating and the first waveplate.

5. The display device according to claim 3, characterized in that, The first refractive device is located between the field mirror and the first liquid crystal grating.

6. The display device according to claim 5, characterized in that, It also includes a second waveplate, which is located between the field lens and the first refractive device, and is used to rotate the polarization direction of the light incident on the second waveplate so that it is parallel to the first direction before being emitted.

7. The display device according to claim 3, characterized in that, The first liquid crystal grating includes a plurality of first grating units arranged along the first direction, and the first grating unit includes a plurality of first electrodes, the length along the first direction being a first length; The first refractive device includes a plurality of first deflection units arranged along the second direction, and the first deflection unit includes a plurality of the third electrodes, the length of which along the second direction is a second length; The second length is greater than the first length.

8. The display device according to claim 1, characterized in that, The liquid crystal grating includes a first substrate, a first electrode, a first liquid crystal layer, a second electrode, and a second substrate arranged sequentially; the vertical distance between the first substrate and the second substrate is D1; The refractive device includes a third substrate, a third electrode, a second liquid crystal layer, a fourth electrode, and a fourth substrate arranged sequentially; the vertical distance between the third substrate and the fourth substrate is D2; D1 < D2.

9. The display device according to claim 8, characterized in that, 50μm≤D2≤100μm.

10. The display device according to claim 1, characterized in that, The frequency at which the liquid crystal grating switches its deflection angle is H1, and the frequency at which the refractive device switches its deflection angle is H2; H1 > H2.

11. The display device according to claim 10, characterized in that, 0.5Hz≤H2≤10Hz.

12. The display device according to claim 3, characterized in that, The first refractive device includes a plurality of first deflection units arranged along the second direction, and the first deflection unit includes a plurality of the third electrodes; The third electrode in at least two of the first deflection units is electrically connected.

13. The display device according to claim 1, characterized in that, The liquid crystal grating includes a first substrate, a first electrode, a first liquid crystal layer, a second electrode, and a second substrate arranged sequentially. In the first liquid crystal grating, a plurality of the first electrodes extend along the fifth direction; The refractive device includes a third substrate, a third electrode, a second liquid crystal layer, a fourth electrode, and a fourth substrate arranged sequentially; the third electrode in the first refractive device extends along a sixth direction; The angle between the fifth direction and the sixth direction is less than or equal to 10°.

14. The display device according to claim 1, characterized in that, The at least one refractive device is located on the side of the grating assembly away from the field mirror.

15. A control method based on the display device as described in claim 1, characterized in that, include: Obtain the target's angle at its location; When the target angle is greater than the threshold angle, at least one refractive device is controlled to operate in the first working mode to deflect the light as a whole by a first preset angle, wherein the first preset angle is greater than zero.

16. The control method according to claim 15, characterized in that, When the target angle is less than or equal to the threshold angle, the refractive device is controlled to operate in the second working mode, deflecting the light as a whole by a second preset angle or not deflecting the light, wherein the second preset angle is less than the first preset angle.

17. The control method according to claim 16, characterized in that, When the target angle is greater than a threshold angle, at least one refractive device is controlled to operate in a first operating mode to deflect the light as a whole by a first preset angle, including: When the target angle is greater than the threshold angle, the first preset angle is obtained based on the target angle; Control at least one refractive device to operate in the first working mode, so that the light rays are deflected as a whole according to the first preset angle.

18. The control method according to claim 16, characterized in that, When the target angle is greater than the threshold angle, after controlling at least one refractive device to operate in the first working mode and deflecting the light as a whole by a first preset angle, the method further includes: The grating deflection angle of the grating component is obtained based on the first preset angle and the target deflection angle.

19. The control method according to claim 18, characterized in that, After obtaining the grating deflection angle of the grating component based on the first preset angle and the target deflection angle, the method further includes: The current first preset angle remains unchanged until the target angle changes.

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