CN117389073A

CN117389073A - Display device and control method thereof

Info

Publication number: CN117389073A
Application number: CN202311448433.9A
Authority: CN
Inventors: 曾洋; 丁渊
Original assignee: Shanghai Tianma Microelectronics Co Ltd
Current assignee: Shanghai Tianma Microelectronics Co Ltd
Priority date: 2023-11-01
Filing date: 2023-11-01
Publication date: 2024-01-12

Abstract

The invention discloses a display device and a control method thereof, wherein the display device comprises a light source, a spatial light modulator, a field lens and a grating component which are sequentially arranged; the light source is used for sequentially emitting coherent backlight beams with multiple colors; the spatial light modulator is used for carrying out phase modulation and/or amplitude modulation on the backlight light beam; the display device further comprises at least one refraction device, the at least one refraction device is located on one side, away from the spatial light modulator, of the field lens and used for deflecting light rays integrally by a first preset angle in a first working mode, the first preset angle is larger than zero, and by means of the technical means, the refraction device is arranged, so that the light rays can be deflected integrally by the first preset angle in the first working mode, the visual angle of the display device is improved, and the user requirements are met.

Description

Display device and control method thereof

Technical Field

The present invention relates to the field of display technologies, and in particular, to a display device and a control method thereof.

Background

In order to meet the demands of people on stereoscopic display of electronic devices, electronic devices with 3D holographic display function become a main development direction in the current display field. The electronic device may implement a 3D holographic display function through an integrated holographic display system.

When an electronic device having a 3D hologram display function displays an image, a left-eye image and a right-eye image are generally formed by a diffraction function of a liquid crystal grating after phase and amplitude modulation of an optical signal by a spatial light modulator (Spatial Light Modulators, SLM). How to improve the display effect becomes a problem to be solved.

Disclosure of Invention

The invention provides a display device and a control method thereof, which are used for improving the visual angle of the display device and meeting the requirements of users.

In a first aspect, an embodiment of the present invention provides a display device, including a light source, a spatial light modulator, a field lens, and a grating assembly sequentially disposed;

the light source is used for sequentially emitting coherent backlight beams with multiple colors;

the spatial light modulator is used for carrying out phase modulation and/or amplitude modulation on the backlight light beam;

the display device further comprises at least one refraction device, wherein the at least one refraction device is located on one side, far away from the spatial light modulator, of the field lens and used for deflecting light rays integrally by a first preset angle in a first working mode, and the first preset angle is larger than zero.

In a second aspect, an embodiment of the present invention further provides a method for controlling a display device, including:

Acquiring a target angle of a position where a target is located;

when the target angle is larger than a threshold angle, controlling at least one refraction device to work in a first working mode, and deflecting the whole light rays by a first preset angle, wherein the first preset angle is larger than zero.

In the display device provided by the embodiment of the invention, at least one refraction device is arranged on one side of the field lens far away from the spatial light modulator. The refraction device can deflect the light integrally by a first preset angle when a user moves to an oblique viewing angle, so that an extra deflection amount is provided on the basis of deflecting the light by the grating component, the deflection angle of the light is increased, the visual angle of the display device is improved, and the user requirement is met.

Drawings

Fig. 1 is a schematic structural diagram of a display device according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of another display device according to an embodiment of the present invention;

FIG. 3 is a schematic view of the display device of FIG. 1 in a second mode of operation;

fig. 4 is a schematic structural diagram of another display device according to an embodiment of the present invention;

FIG. 5 is a schematic top view of a first liquid crystal grating according to an embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view taken along line AA' of FIG. 5;

Fig. 7 is a schematic top view of a first refractive device according to an embodiment of the present invention;

FIG. 8 is a schematic cross-sectional view taken along BB' in FIG. 7;

FIG. 9 is a schematic top view of a second liquid crystal grating according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of another display device according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of another display device according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of another display device according to an embodiment of the present invention;

FIG. 13 is a schematic diagram illustrating connection of a third electrode in a first deflection device according to an embodiment of the present invention;

fig. 14 is a schematic top view of a second refractive device according to an embodiment of the present invention;

FIG. 15 is a schematic cross-sectional view taken along CC' of FIG. 14;

FIG. 16 is another schematic cross-sectional view taken along CC' of FIG. 14;

FIG. 17 is a schematic view in section along CC' of FIG. 14;

FIG. 18 is a schematic view in section along CC' of FIG. 14;

FIG. 19 is a schematic view in section along CC' of FIG. 14;

FIG. 20 is a schematic top view of a third refractive device according to an embodiment of the present invention;

FIG. 21 is a schematic cross-sectional view taken along DD' in FIG. 20;

fig. 22 is a flowchart of a control method of a display device according to an embodiment of the present invention;

Fig. 23 is a flowchart illustrating another control method of a display device according to an embodiment of the present invention;

fig. 24 is a flowchart of a control method of a display device according to another embodiment of the present invention.

Detailed Description

The invention is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.

Fig. 1 is a schematic structural diagram of a display device according to an embodiment of the present invention, and as shown in fig. 1, 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 refraction device 50 (one refraction device 50 is schematically shown in fig. 1). The light source 10 is used to time-sequentially emit coherent backlight beams of multiple colors. The backlight beams with the colors which are emitted in time sequence. For example, the light source 10 may employ a backlight module, and the backlight module may emit red backlight beam, green backlight beam and blue backlight beam in a time-sharing manner to realize the image display of the display device.

The spatial light modulator 20 is used for phase modulating and/or amplitude modulating the backlight beam. The field lens 30 is used to focus light into a viewing window at the eye position so that the eye can see an image displayed by the display device. That is, the light modulated by the spatial light modulator 20 can be incident on the grating assembly 40 through the field lens 30, thereby forming a left-eye image and a right-eye image. The refraction device 50 is located on a side of the field lens 30 away from the spatial light modulator 20, and the refraction device 50 is configured to deflect the light beam as a whole by a first preset angle in the first operation mode, where the first preset angle is greater than zero. As a comparative example, in the prior art, since the deflection angle of the grating assembly 40 to the light is limited, the diffraction efficiency of the light is low under a large viewing angle, and it is difficult to satisfy the viewing requirement of the user, in other words, in the prior art, when the user is at the central viewing position of the display device, the left eye and the right eye can perform clearer imaging, however, in the case that the position of the display device is not changed, when the user moves from the central viewing position of the display device to the oblique viewing angle, the user experience effect is poor because the grating assembly 40 cannot deflect the light at a large angle. In the embodiment of the invention, by arranging at least one refraction device 50 on the side of the field lens 30 away from the spatial light modulator 20, when a user moves to a strabismus angle, the light can be deflected by a first preset angle as a whole, so that even if the user is far from the central viewing position of the display device, the light can be deflected to the human eyes by the refraction device 50, the visual angle of the display device can be improved, and the user requirement can be met.

With continued reference to fig. 1, refractive device 50 may be located on a side of grating assembly 40 remote from field lens 30. In other embodiments, the refractive device 50 may have other placement locations.

Fig. 2 is a schematic structural diagram of another display device according to an embodiment of the present invention, and as shown in fig. 2, a refraction device 50 may be further located between the grating assembly 40 and the field lens 30.

Referring to fig. 1 and 2, the number of refractive devices 50 is 1. In other embodiments, the number of refractive devices 50 may be multiple. At least two of the plurality of refractive devices 50 may have the same azimuthal angle or a similar azimuthal angle of deflection of the light. Therefore, the light deflection with a larger angle is realized by the deflection superposition of at least two deflection plates with the same azimuth angle or similar azimuth angles.

In the display device according to the embodiment of the invention, at least one refraction device 50 is disposed on the side of the field lens 30 away from the spatial light modulator 20. The refraction device 50 can deflect the light beam by a first preset angle when the user moves to the oblique viewing angle, so that an additional deflection amount is provided on the basis of deflecting the light beam by the grating assembly 40, the deflection angle of the light beam is increased, the viewing angle of the display device is improved, and the user requirement is met.

Fig. 3 is a schematic view of the display device shown in fig. 1 in a second operation mode, and referring to fig. 1 and 3, the refraction device 50 is further configured to deflect light by a second preset angle or not in the second operation mode, where the second preset angle is smaller than the first preset angle. The refractive device 50 deflects light at a greater angle in the first mode of operation than in the second mode of operation, such that the refractive device 50 provides a greater amount of additional deflection in the first mode of operation than in the second mode of operation based on the deflection of light by the grating assembly 40. Alternatively, the refractive device 50 does not provide an additional amount of deflection in the second mode of operation.

Illustratively, the user is in a viewing position away from the center of the display device in the first mode of operation (left eye a and right eye b are in viewing positions away from the center of the display device) when having a large oblique viewing angle. In the second mode of operation the user is in a viewing position near the centre of the display device (left eye a and right eye b are in a viewing position near the centre of the display device) with a small oblique viewing angle.

Fig. 4 is a schematic structural diagram of another display device according to an embodiment of the present invention, and referring to fig. 4, the display device includes two spatial light modulators 20, where the two spatial light modulators 20 are a phase spatial light modulator 201 and an amplitude spatial light modulator 202. The phase spatial light modulator 201 is used for phase modulating the backlight beam, and the amplitude spatial light modulator 202 is used for amplitude modulating 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. Three liquid crystal gratings 401 are illustrated in fig. 4, and 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, respectively.

Fig. 5 is a schematic top view of a first liquid crystal grating according to an embodiment of the present invention, fig. 6 is a schematic cross-sectional view along AA' in fig. 5, and referring to fig. 5 and 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 sequentially disposed. 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.

Illustratively, 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, and by providing the first dielectric layer 4016 and the second dielectric layer 4017, on one hand, the liquid crystal grating 401 can be protected, on the other hand, the liquid crystal grating 401 is prevented from being damaged by an external environment, on the other hand, charges between the electrodes can be effectively isolated, leakage of charges and occurrence of electric arcs can be prevented, and normal operation of the liquid crystal grating 401 can be ensured.

Illustratively, the first liquid crystal layer 4013 includes liquid crystal molecules, the first electrode 4012 may be a plurality and independently disposed, and the second electrode 4014 may be a full-face electrode. A voltage difference exists between the first electrode 4012 and the second electrode 4014, so that a longitudinal electric field formed by the first electrode 4012 and the second electrode 4014 can drive liquid crystal molecules in the first liquid crystal layer 4013 to rotate, and further can refract light incident on the liquid crystal grating 401.

Fig. 7 is a schematic top view of a first refractive device according to an embodiment of the present invention, and fig. 8 is a schematic cross-sectional view along BB' in fig. 7. As shown in fig. 7 and 8, 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 sequentially disposed. 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.

Illustratively, the second liquid crystal layer 503 includes liquid crystal molecules, and the third electrode 502 may be a plurality of electrodes that are independently disposed and may also be a full-face electrode. The fourth electrode 504 may be a full-face electrode, and a voltage difference exists between the third electrode 502 and the fourth electrode 504, so that a 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, and further can refract the light incident to the refraction device 50. Unlike the liquid crystal grating 401 that deflects light using diffraction, the refractive device 50 deflects light using refraction. Referring to fig. 4 to 8, the liquid crystal grating 401 includes a first liquid crystal grating 41, and a plurality of first electrodes 4012 in the first liquid crystal grating 41 are disposed apart from each other along a first direction X. The plurality of first electrodes 4012 provided at intervals are arranged along the first direction X. Adjacent two first electrodes 4012 are spaced apart from each other by a certain distance in the first direction X, and are not in physical contact. The at least one refractive device 50 includes a first refractive device 51, and a plurality of third electrodes 502 in the first refractive device 51 are spaced apart from each other along the second direction Y. The plurality of third electrodes 502 disposed at intervals from each other are arranged along the second direction Y. In the second direction Y, adjacent two third electrodes 502 are spaced apart by a certain distance and are not in physical contact. The included angle between the first direction X and the second direction Y is smaller than or equal to 10 degrees. In the embodiment of the present invention, the refraction device 50 is implemented by 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, so that the first refractive device 51 provides an additional deflection amount based on the deflection of the light by the first liquid crystal grating 41, and superposition of the deflection of the light along the first direction X is realized. The light ray deflection in the first direction X is, for example, a light ray deflection in the horizontal direction (0 degree azimuth).

For example, as shown in fig. 5 to 8, the angle between the first direction X and the second direction Y is ω, ω is greater than or equal to 1 ° and ω is less than or equal to 10 °.1 DEG.ltoreq.ω.ltoreq.10 DEG, a slight angle exists between the first direction X and the second direction Y, and the first direction X is not parallel to the second direction Y, thereby reducing the moire formed between the first liquid crystal grating 41 and the first refractive device 51 and improving the display quality of the display device.

Fig. 9 is a schematic top view of a second liquid crystal grating according to an embodiment of the present invention, and fig. 10 is a schematic structural view of a display device according to another embodiment of the present invention, and referring to fig. 6, fig. 9 and fig. 10, a plurality of liquid crystal gratings 401 includes 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. The plurality of first electrodes 4012 in the second liquid crystal grating 42 are arranged at intervals from each other along the third direction Z. The plurality of first electrodes 410 disposed at a distance from each other are arranged along the third direction Z. In the third direction Z, adjacent two first electrodes 4012 are spaced apart by a certain distance and are not in physical contact. The angle between the first direction X and the third direction Z is 45 °.

As shown in fig. 10, the display device further includes a first wave plate 61. The first wave plate 61 may be understood as an optical rotation plate capable of changing the polarization direction of light. The first wave plate 61 is located between the first liquid crystal grating 41 and the second liquid crystal grating 42, and is configured to rotate the polarization direction of the light incident on the first wave plate 61 to be parallel to the third direction Z and then emit the light. 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 disposing the first wave plate 61 between the first liquid crystal grating 41 and the second liquid crystal grating 42, the first wave plate 61 can rotate the light until the polarization direction of the light coincides with the third direction Z, that is, the first wave plate 61 rotates the light until the polarization direction of the light coincides with the direction of the polarized light of the second liquid crystal grating 42, so as to adapt the long axis direction of the liquid crystal molecules in the second liquid crystal grating 42 to the polarization direction of the light projected to the second liquid crystal grating 42. The first refraction device 51 is located between the first liquid crystal grating 41 and the first wave plate 61, and the first refraction device 51 with the same or similar direction of the polarized light is arranged adjacent to the first liquid crystal grating 41, so that an optical rotation element is not required to be separately and additionally arranged for the first refraction device 51, the arrangement mode is simple, and the display device is compact in structure.

Fig. 11 is a schematic structural diagram of another display device according to an embodiment of the present invention, as shown in fig. 11, a first refraction 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, and if the backlight beam is X polarized in the first direction, no wave plate is provided between the first liquid crystal grating 41 and the field lens 30. The first refraction device 51 and the first liquid crystal grating are adjacently 41 arranged, which have the same or similar direction of the deflected light, so that an optical rotation element is not required to be separately and additionally arranged for the first refraction device 51, the arrangement mode is simple, and the display device has compact structure.

Fig. 12 is a schematic structural diagram of another display device according to an embodiment of the present invention, and as shown in fig. 12, the display device further includes a second wave plate 62, where the second wave plate 62 is located between the field lens 30 and the first refractive device 51, and is configured to rotate the polarization direction of the light incident on the second wave plate 62 to be parallel to the first direction X and then emit the light. Since the backlight beam emitted from the light source 10 is linearly polarized, and if the backlight beam is not polarized in the first direction X, a second wave plate 62 needs to be disposed between the first liquid crystal grating 41 and the field lens 30, that is, a second wave plate 62 is disposed between the field lens 30 and the first refraction device 51, so that the second wave plate 62 can rotate the polarization direction of the light incident on the second wave plate 62 to be parallel to the first direction X, and then emit the light to the first refraction device 51, so as to adapt the long axis direction of the liquid crystal molecules in the first refraction device 51 and the polarization direction of the light incident on the first refraction device 51. Since the first refraction device 51 and the first liquid crystal grating 41 have similar deflection directions of light, the first refraction device 51 is arranged adjacent to the first liquid crystal grating 41, so that an optical rotation element is not required to be separately and additionally arranged for the first liquid crystal grating 41, the arrangement mode is simple, and the display device has compact structure.

With continued reference to fig. 6 and 8, the first liquid crystal grating 41 includes a plurality of first grating units 411 aligned in the first direction X. In the first liquid crystal grating 41, a plurality of first grating units 411 are repeatedly arranged along the first direction X. The first grating unit 411 includes a plurality of first electrodes 4012, and a 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 deflecting units 511 arranged in the second direction Y. In the first refractive device 51, the plurality of first deflecting units 511 are repeatedly arranged along the second direction Y. The first deflecting unit 511 includes a plurality of third electrodes 502, and the length of the first deflecting 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 the first electrodes 4012 in each first grating unit 411 in the first liquid crystal grating 41 varies from frame to frame. Thus, the first length K1 varies from frame to frame. The number of the third electrodes 502 in each first deflecting unit 511 in the first refractive device 51 is not changed regardless of the change of the frame. Thus, the second length K2 may be a fixed value. In the embodiment of the present invention, no matter how the first length K1 changes with different frames, the first length K1 is smaller than the second length K2. Thus, the first refractive device 51 using the refraction principle has a larger period cell length than the first grating cell 411 using the diffraction principle. Wherein one frame is a period in which one color light is irradiated to one eye of the observer.

Illustratively, in the second direction Y, the distance between the centers of adjacent two third electrodes 502 is greater than or equal to 5 μm and less than or equal to 10 μm.

With continued reference to fig. 6 and 8, the grating assembly 40 includes a plurality of liquid crystal gratings 401, the liquid crystal gratings 401 including a first substrate 4011, a first electrode 4012, a first liquid crystal layer 4013, a second electrode 4014, and a second substrate 4015, which are disposed in that order. 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, which are sequentially disposed. The vertical distance between the third substrate 502 and the fourth substrate 505 is D2. D1 < D2, that is, the thickness of the liquid crystal cell of the refraction device 50 is greater than that of the liquid crystal cell of the liquid crystal grating 401, so that the liquid crystal grating 401 deflects light by diffraction, and the refraction device 50 deflects the device by refraction, so that the refraction device 50 provides an additional deflection amount on the basis of deflecting the light by the liquid crystal grating 401, and superposition of light deflection is realized.

With continued reference to FIG. 8, D2 satisfies 50 μm.ltoreq.D2.ltoreq.100 μm, thus enabling the deflection of light by the refractive device 50. If D2 is less than 50 μm, the cell thickness of the refractive device 50 is too small to achieve a sufficiently large angle of light deflection. If D2 is greater than 100 μm, the cell thickness of the refractive device 50 is too great, providing an excessive light deflection angle that will not be used at all. And an increase in the cell thickness results in an increase in the thickness of the display device and a decrease in the liquid crystal response rate. In the embodiment of the invention, the D2 is set to be more than or equal to 50 mu m and less than or equal to 100 mu m, and the thickness of the box is reduced and the response speed of liquid crystal is increased on the basis of providing light deflection with a proper angle.

With continued reference to fig. 4, the grating assembly 40 includes a plurality of liquid crystal gratings 401, the liquid crystal gratings 401 switching the angle of deflection at a frequency H1 and the refractive device 50 switching the angle of deflection at a frequency H2. H1 > H2, i.e., the frequency at which the refractive device 50 switches the angle of deflection is less than the frequency at which the liquid crystal grating 401 switches the angle of deflection. Therefore, a lower switching voltage than the frequency of the liquid crystal grating 401 can be provided for the refraction device 50, and the control difficulty of the refraction device 50 is reduced.

It will be appreciated that the number and/or voltage of the first electrodes 4012 within each first grating unit 411 in the first liquid crystal grating 41 varies from frame to frame. The amount of voltage change on the first electrode 4012 per second is the frequency H1. The number of the third electrodes 502 in each first deflecting unit 511 in the first refraction device 51 is unchanged, and the voltage of the third electrodes 502 in each first deflecting unit 511 in the first refraction device 51 is changed every multiple frames. No change typically occurs between two adjacent frames. The amount of voltage change on the third electrode 502 per second is the frequency H2.

Optionally, H2 satisfies 0.5 Hz.ltoreq.H2.ltoreq.10Hz. If H2 is less than 0.5Hz, the frequency of the refractive device 50 for switching the deflection angle is too small to timely follow the movement of the human eye to switch the deflection angle; if H2 is greater than 10Hz, the frequency at which the refractive device 50 switches the deflection angle is too great, providing an excessive switching frequency that will not be used at all. And an increase in the frequency at which the refractive device 50 switches the angle of deflection results in an increase in the difficulty of controlling the refractive device 50. In the embodiment of the invention, H2 which is more than or equal to 0.5Hz and less than or equal to 10Hz is set, and the control difficulty of the refraction device 50 is reduced on the basis of providing proper switching frequency.

Fig. 13 is a schematic diagram showing connection of third electrodes in the first deflecting device according to the embodiment of the present invention, as shown in fig. 13, the first deflecting device 51 includes a plurality of first deflecting units 511 arranged along the second direction Y, and the first deflecting unit 511 includes a plurality of third electrodes 502. The third electrodes 502 in at least two first deflection units 511 are electrically connected in such a way that the control is simple.

With continued reference to fig. 6, the number of the first electrodes 4012 in each first grating unit 411, that is, the number of the first electrodes 4012 in each first grating unit 411, is varied from 4 to several hundred according to the change of the display screen, so that the diffraction angle is changed. Therefore, in the liquid crystal grating 401, each of the first electrodes 4012 is individually controlled. However, for the refraction device 50, the number of the third electrodes 502 in each first refraction unit 511 does not need to be changed according to the change of the display device picture, that is, the number of the third electrodes 502 in each first refraction unit 511 is the same, so that the third electrodes 502 with the same number in each first refraction unit 511 can be connected to the same source signal line, and in total, only 10-20 groups of source signal lines are needed to realize the control of the third electrodes 502, so that the control mode is simple.

Fig. 14 is a schematic top view of a second refractive device according to an embodiment of the present invention, fig. 15 is a schematic cross-sectional view along CC 'in fig. 14, fig. 16 is another schematic cross-sectional view along CC' in fig. 14, and as shown in fig. 14-16, 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 sequentially disposed. The at least one refractive device 50 includes a second refractive device 52, and the second refractive device 52 further includes a prism profile defining layer 520, and the prism profile defining layer 520 is located between the fourth electrode 504 and the fourth substrate 505 and includes a plurality of prism profile defining units 5201 arranged along the fourth direction W. The prism profile defining units 5201 shown in fig. 15 and 16 are arranged in the fourth direction W, and the fourth direction W is the same as the second direction Y. It will be appreciated that in other embodiments, the fourth direction W may also be different from the second direction Y.

Illustratively, the material of the prism topography defining unit 5201 may be an imprint resin or the like. The refractive index of the resin is about 1.5.

Referring to fig. 15, in the fourth direction W, the thickness of the prism topography-defining unit 5201 gradually decreases. Alternatively, referring to fig. 16, in 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 in a direction perpendicular to the plane in which the fourth substrate 505 is located.

If the refractive index of the resin used in the prism pattern defining unit 5201 is closer to the refractive index of e-ray, the liquid crystal molecules are not biased when no voltage is applied to the third electrode 502 and the fourth electrode 503. If the refractive index of the resin used by the prism topography defining unit 5201 is closer to the o-ray refractive index, the liquid crystal molecules are biased when no voltage is applied to the third electrode 502 and the fourth electrode 503. In one embodiment, no voltage is applied to the third electrode 502 and the fourth electrode 503, and the refractive index of the liquid crystal molecules is different from that of the resin, so that the light incident on the second refractive device 52 is deflected; the third electrode 502 and the fourth electrode 503 are applied with voltages, the refractive index of the liquid crystal molecules is the same as that of the resin, and the light incident on the second refractive device 52 is not deflected. In another embodiment, a 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 the light incident on the second refractive device 52 is deflected; the refractive index of the liquid crystal is the same as that of the resin without applying a voltage to the third electrode 502 and the fourth electrode 503, and the light incident on the second refractive device 52 is not deflected. In general, a large voltage is applied to the third electrode 502 and the fourth electrode 503 so that all liquid crystal molecules stand up, and thus the second refraction device 52 deflects the light that can be incident.

Fig. 17 is a schematic cross-sectional view along CC' in fig. 14, as shown in fig. 17, the plurality of prism shape defining units 5201 share the same third electrode 502, and the plurality of prism shape defining units 5201 share the same fourth electrode 503, i.e., the third electrode 502 and the fourth electrode 503 are all surface electrodes, so that the second refraction device 52 has a simple manufacturing process and a simple control method.

With continued reference to fig. 15 and 16, the plurality of third electrodes 502 are disposed at intervals from each other in the fourth direction W, that is, in the fourth direction W, adjacent two third electrodes 502 are spaced a distance apart from each other and are not in physical contact. The plurality of prism morphology defining units 5021 share the same fourth electrode. When a voltage is applied to the third electrode 502 and the fourth electrode 503, the third electrode 502 and the fourth electrode 503 are close to each other, the electric field intensity is high, the rotation angle of the liquid crystal molecules is large, and the rotation angles of the liquid crystal molecules at different positions are different in the same horizontal direction.

The adjacent two third electrodes 502 are spaced a certain distance, that is, the third electrodes 502 are pixel electrodes driven independently, a small voltage can be applied to the pixel electrodes at the positions where the third electrodes 502 and the fourth electrodes 503 are close to each other, and a large voltage can be applied to the pixel electrodes at the positions where the third electrodes 502 and the fourth electrodes 503 are far from each other, so that the standing angles of the liquid crystal molecules at all positions are the same, and the liquid crystal layer under the condition of power-up can be used as a film layer with uniformly distributed refractive indexes, thereby improving the accuracy of the second refraction device 52 for deflecting light.

Fig. 18 is a schematic view of another cross section along CC' in fig. 14, and as shown in fig. 18, the display device includes a first display area 71 and a second display area 72 arranged along a fourth direction W. Illustratively, the first display area 71 may be a left display area of the display device and the second display area 72 may be a right display area of the display device.

The prism profile defining unit 5201 includes a first prism profile defining unit 521 and a second prism profile defining unit 522, the first prism profile defining unit 521 being located in the first display area 71 and the second prism profile defining unit 522 being located in the second display area 72. In the fourth direction W, the thickness of the first prism topography-defining unit 521 gradually decreases, and the thickness of the second prism topography-defining unit 522 gradually increases. In other words, along the fourth direction W, the thickness variation of the first prism topography defining unit 521 in the first display area 71 is opposite to the thickness variation of the second prism topography defining unit 522 in the second display area 72, so that the light is deflected to the left by the deflecting device 50 in the first display area 71 and to the right by the deflecting device 50 in the second display area 72. Alternatively, fig. 19 is a schematic cross-sectional view of CC' in fig. 14, and as shown in fig. 19, the thickness of the first prism topography-defining unit 521 gradually increases and the thickness of the second prism topography-defining unit 522 gradually decreases along the fourth direction W. This enables, on the one hand, the light to be deflected to the left by the deflecting means 50 in the first display region 71 and to be deflected to the right by the deflecting means 50 in the second display region 72, and on the other hand, a diversified arrangement of display devices to be achieved.

Fig. 20 is a schematic top view of a third refraction device according to an embodiment of the present invention, and fig. 21 is a schematic cross-sectional view along DD' in fig. 20. As shown in fig. 20 and 21, at least one refraction device 50 further includes a third refraction device 53, where a plurality of third electrodes 502 in the third refraction device 53 are disposed at intervals along a fifth direction V. The plurality of third electrodes 502 disposed at intervals from each other are arranged in the fifth direction V. In the fifth direction V, adjacent two third electrodes 502 are spaced apart by a distance and are not in physical contact. The angle between the first direction X and the fifth direction V is 90 °.

With continued reference to fig. 5-7, the grating assembly 40 includes a plurality of liquid crystal gratings 401, the liquid crystal gratings 401 including a first substrate 4011, a first electrode 4012, a first liquid crystal layer 4013, a second electrode 4014, and a second substrate 4015 disposed in that order; the liquid crystal grating 401 includes a first liquid crystal grating 41, and a plurality of first electrodes 4012 in the first liquid crystal grating 41 extend in the 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, which are sequentially disposed. The at least one refractive device 50 comprises a first refractive device 51, the third electrode in the first refractive device 51 extending in the sixth direction. The included angle theta between the fifth direction and the sixth direction is less than or equal to 10 degrees. The direction of arrangement of the electrodes is perpendicular to the extending direction. In other embodiments, it 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 refraction device 51, so that the first refraction device 51 provides an additional deflection amount on the basis of deflecting the light by the first liquid crystal grating 41, and superposition of light deflection is realized.

With continued reference to fig. 1, at least one refractive device 50 is located on a side of grating assembly 40 remote from field lens 30. The number of refractive devices 50 may be one. The number of refractive devices 50 may also be plural. At least two of the plurality of refractive devices 50 may have the same azimuthal angle or a similar azimuthal angle of deflection of the light. Therefore, the light deflection with a larger angle is realized by the deflection superposition of at least two deflection plates with the same azimuth angle or similar azimuth angles.

In summary, the display device provided in the embodiment of the present invention is provided with at least one refraction device 50 on the side of the field lens 30 away from the spatial light modulator 20. The refraction device 50 can deflect the light beam by a first preset angle when the user moves to the oblique viewing angle, so that an additional deflection amount is provided on the basis of deflecting the light beam by the grating assembly 40, and the deflection angle of the light beam is increased, so that the visual angle of the display device is improved, and the user requirement is met.

Based on the same inventive concept, the embodiment of the present invention further provides a control method of a display device, where the control method is implemented based on the display device in the foregoing embodiment, and fig. 22 is a schematic flow chart of the control method of the display device provided by the embodiment of the present invention, and as shown in fig. 22, the control method includes:

S101, acquiring a target angle of a position where a target is located.

In particular, the target may be understood as at least one of the center of the pupil of the left eye or the center of the pupil of the right eye of the user. It will be appreciated that as the user moves in the right eye direction, the angle between the right eye pupil center and the user's right eye pupil center when in the display device center viewing position needs to be taken as the target angle due to the greater right side deflection angle. When the user moves in the left eye direction, since the left-side deflection angle is larger, it is necessary to set the angle between the left-eye pupil center and the left-eye pupil center when the user is at the display device center viewing position as the target angle.

S102, when the target angle is larger than a threshold angle, controlling at least one refraction device to work in a first working mode, and deflecting the whole light rays by a first preset angle, wherein the first preset angle is larger than zero.

Specifically, when the target angle is greater than the threshold angle, it is indicated that the user moves from the central viewing position of the display device to the oblique viewing angle, and the grating assembly cannot deflect the light in a large angle, so that the user experience effect is poor. According to the embodiment of the invention, when a user is in an oblique viewing angle, the refraction device deflects the light rays integrally by a first preset angle, so that even if the user is far away from the central viewing position of the display device, the refraction device can deflect the light rays to human eyes, the visual angle of the display device can be improved, and the user requirement is met.

Illustratively, the user is in a viewing position away from the center of the display device in the first mode of operation (left and right eyes are in viewing positions away from the center of the display device) when there is a large oblique viewing angle.

It will be appreciated that when the user is facing the display device, the angle of deflection of the lc grating between the eyes is about 2.48 °, and when it exceeds 2.48 °, the deflection of light cannot be achieved with the lc grating alone. For example, the threshold angle may be 4 °, and when the target angle is greater than the threshold angle, the light is deflected to the human eye by the refractive device, so that the viewing angle of the display device may be improved, and the user requirement may be satisfied.

And S103, when the target angle is smaller than or equal to the threshold angle, controlling the refraction device to work in a second working mode, and deflecting the whole light rays by a second preset angle or not deflecting the light rays, wherein the second preset angle is smaller than the first preset angle.

Specifically, when the target angle is smaller than or equal to the threshold angle, the refraction device is in the second working mode, the refraction device can deflect the light wholly by a second preset angle or does not deflect the light, and the second preset angle is smaller than the first preset angle. The refractive device deflects light at a greater angle in the first mode of operation than in the second mode of operation, such that the refractive device provides a greater amount of additional deflection in the first mode of operation than in the second mode of operation based on the deflection of the light by the grating assembly. Alternatively, the refractive device does not provide an additional amount of deflection in the second mode of operation.

Illustratively, the user is in a second mode of operation in a viewing position near the center of the display device (left and right eyes are in a viewing position near the center of the display device) with a small oblique viewing angle.

According to the control method of the display device, the target angle of the position of the target is obtained, when the target angle is larger than the threshold angle, at least one refraction device is controlled to work in the first working mode, and the light is deflected integrally by the first preset angle, so that even if a user is far away from the central viewing position of the display device, the light can be deflected to human eyes through the refraction device, the visual angle of the display device can be improved, and the user requirements are met. In addition, when the target angle is smaller than or equal to the threshold angle, the refraction device is controlled to work in the second working mode, and the refraction device can deflect the light in the whole by a second preset angle or not to deflect the light because the user is in a central viewing position close to the display device in the second working mode.

Fig. 23 is a flowchart of another control method of a display device according to an embodiment of the present invention, where, based on the above embodiment, fig. 23 further illustrates an operation of controlling at least one refractive device to operate in a first operation mode and deflecting light integrally by a first preset angle when a target angle is greater than a threshold angle, and as shown in fig. 23, the control method includes:

S201, acquiring a target angle of the position of the target.

S202, when the target angle is larger than a threshold angle, acquiring a first preset angle according to the target angle.

Specifically, a first preset angle is obtained according to the deflection angle of the eyes of the user, so that the refraction device deflects light rays according to the first preset angle, and the viewing requirement of the user is met.

S203, controlling at least one refraction device to work in a first working mode, and deflecting the whole light according to a first preset angle.

Specifically, according to the obtained first preset angle, the refraction device is controlled to work in the first working mode, light rays are deflected integrally according to the first preset angle, so that the control precision is high, and the watching requirement of a user can be met.

S204, when the target angle is smaller than or equal to the threshold angle, controlling the refraction device to work in a second working mode, and deflecting the whole light rays by a second preset angle or not, wherein the second preset angle is smaller than the first preset angle.

According to the control method of the display device, when the target angle is larger than the threshold angle, the first preset angle is obtained according to the target angle, and the refraction device is controlled to integrally deflect the light rays by the first preset angle, so that the control accuracy is high.

Fig. 24 is a flowchart of a control method of a display device according to another embodiment of the present invention, where, based on the above embodiment, fig. 24 further illustrates an operation of controlling at least one refractive device to operate in a first operation mode when a target angle is greater than a threshold angle, and after deflecting light integrally by a first preset angle, as shown in fig. 24, the control method includes:

s301, acquiring a target angle of a position where a target is located.

S302, when the target angle is larger than a threshold angle, controlling at least one refraction device to work in a first working mode, and deflecting the whole light by a first preset angle, wherein the first preset angle is larger than zero.

S303, acquiring the grating deflection angle of the grating component according to the first preset angle and the target deflection angle.

In particular, the target deflection angle may be understood as the angle at which the user's eyes deflect. The grating deflection angle of the grating component can be calculated by subtracting the first preset angle from the target deflection angle, so that the grating component can deflect according to the grating deflection angle.

S304, keeping the current first preset angle unchanged until the target angle changes.

Specifically, the target angle does not change, which means that the user viewing angle does not change, so that the user viewing angle does not change, and the current first preset angle can be kept unchanged, so that the refraction device deflects the whole body by the first preset angle and then the light is incident to the eyes of the user. When the visual angle of the user changes, the position of the user is indicated to move, and the first preset angle can be obtained according to the target angle or the light is not deflected, so that the overall deflection angle of the light is changed.

And S305, controlling the refraction device to work in a second working mode when the target angle is smaller than or equal to the threshold angle, and deflecting the whole light by a second preset angle, wherein the second preset angle is smaller than the first preset angle.

According to the control method of the display device, when the target angle is larger than the threshold angle, at least one refraction device is controlled to work in the first working mode, after light rays are deflected integrally by the first preset angle, the grating deflection angle of the grating assembly is obtained according to the first preset angle and the target deflection angle, and therefore the grating assembly deflects according to the grating deflection angle. In addition, the current first preset angle is kept unchanged until the target angle is changed, that is, the visual angle of the user is not changed, so that the current first preset angle can be kept unchanged, and the refraction device is ensured to deflect the whole body by the first preset angle and then the light is incident to eyes of the user. When the visual angle of the user changes, a first preset angle can be obtained according to the target angle so as to change the overall deflection angle of the light, and therefore the working stability and reliability of the display device can be ensured.

Note that the above is only a preferred embodiment of the present invention and the technical principle applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, and that various obvious changes, rearrangements, combinations, and substitutions can be made by those skilled in the art without departing from the scope of the invention. Therefore, while the invention has been described in connection with the above embodiments, the invention is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the invention, which is set forth in the following claims.

Claims

1. The display device is characterized by comprising a light source, a spatial light modulator, a field lens and a grating component which are sequentially arranged;

2. The display device of claim 1, wherein the refractive means is further configured to deflect light rays in the second mode of operation as a whole by a second predetermined angle or not, the second predetermined angle being smaller than the first predetermined angle.

3. The display device of claim 1, wherein the grating assembly comprises a plurality of liquid crystal gratings comprising a first substrate, a first electrode, a first liquid crystal layer, a second electrode, and a second substrate disposed in sequence;

the liquid crystal grating comprises a first liquid crystal grating, and a plurality of first electrodes in the first liquid crystal grating are arranged at intervals along a first direction;

The refraction device comprises a third substrate, a third electrode, a second liquid crystal layer, a fourth electrode and a fourth substrate which are sequentially arranged; the at least one refraction device comprises a first refraction device, and a plurality of third electrodes in the first refraction device are arranged at intervals along a second direction;

an included angle between the first direction and the second direction is smaller than or equal to 10 degrees.

4. A display device according to claim 3, wherein the angle between the first direction and the second direction is greater than or equal to 1 °.

5. A display device according to claim 3, wherein the liquid crystal grating comprises a second liquid crystal grating, the first liquid crystal grating being located between the field lens and the second liquid crystal grating;

the first electrodes in the second liquid crystal grating are arranged at intervals along a third direction, and an included angle between the first direction and the third direction is 45 degrees;

the display device further comprises a first wave plate, wherein the first wave plate is positioned between the first liquid crystal grating and the second liquid crystal grating and is used for rotating the polarization direction of light rays entering the first wave plate to be parallel to the third direction and then emergent;

The first refraction device is positioned between the first liquid crystal grating and the first wave plate.

6. A display device as claimed in claim 3, characterized in that the first refractive means are located between the field lens and the first liquid crystal grating.

7. The display device according to claim 6, further comprising a second wave plate between the field lens and the first refractive device for rotating a polarization direction of light incident to the second wave plate to be parallel to the first direction and then emitting the light.

8. A display device according to claim 3, wherein the first liquid crystal grating comprises a plurality of first grating units arranged along the first direction, the first grating units comprising a plurality of the first electrodes, a length along the first direction being a first length;

the first refraction device comprises a plurality of first deflection units arranged along the second direction, the first deflection units comprise a plurality of third electrodes, and the length along the second direction is a second length;

the second length is greater than the first length.

9. The display device of claim 1, wherein the grating assembly comprises a plurality of liquid crystal gratings comprising a first substrate, a first electrode, a first liquid crystal layer, a second electrode, and a second substrate disposed in sequence; the vertical distance between the first substrate and the second substrate is D1;

The refraction device comprises a third substrate, a third electrode, a second liquid crystal layer, a fourth electrode and a fourth substrate which are sequentially arranged; the vertical distance between the third substrate and the fourth substrate is D2; d1 is less than D2.

10. The display device according to claim 9, wherein 50 μm-D2-100 μm.

11. The display device of claim 1, wherein the grating assembly comprises a plurality of liquid crystal gratings, the liquid crystal gratings switching off angle having a frequency H1 and the refractive element switching off angle having a frequency H2;

H1＞H2。

12. the display device according to claim 11, wherein 0.5Hz is equal to or less than H2 is equal to or less than 10Hz.

13. A display device according to claim 3, wherein the first refractive device includes a plurality of first deflection units arranged in the second direction, the first deflection units including a plurality of the third electrodes;

the third electrodes in at least two of the first deflection units are electrically connected.

14. The display device according to claim 1, wherein the refractive device includes a third substrate, a third electrode, a second liquid crystal layer, a fourth electrode, and a fourth substrate, which are sequentially disposed; the at least one refraction device comprises a second refraction device, the second refraction device further comprises a prism topography defining layer, the prism topography defining layer is positioned between the fourth electrode and the fourth substrate and comprises a plurality of prism topography defining units arranged along a fourth direction;

Along the fourth direction, the thickness of the prism topography defining unit is gradually increased or gradually decreased; the thickness of the prism morphology defining unit is the thickness of the prism morphology defining unit along the direction perpendicular to the plane where the fourth substrate is located.

15. The display device according to claim 14, wherein a plurality of the prism topography defining units share the same third electrode, and a plurality of the prism topography defining units share the same fourth electrode.

16. The display device according to claim 14, wherein a plurality of the third electrodes are disposed at intervals from each other in the fourth direction, and a plurality of the prism topography-defining units share the same fourth electrode.

17. The display device according to claim 14, comprising a first display area and a second display area arranged along the fourth direction;

the prism morphology defining unit comprises a first prism morphology defining unit and a second prism morphology defining unit, the first prism morphology defining unit is located in the first display area, and the second prism morphology defining unit is located in the second display area;

Along the fourth direction, the thickness of the first prism topography defining unit is gradually reduced, and the thickness of the second prism topography defining unit is gradually increased; alternatively, in the fourth direction, the thickness of the first prism topography defining unit is gradually increased, and the thickness of the second prism topography defining unit is gradually decreased.

18. A display device according to claim 3, wherein the at least one refractive means further comprises third refractive means in which a plurality of the third electrodes are arranged at intervals from each other in a fifth direction;

the included angle between the first direction and the fifth direction is 90 degrees.

19. The display device of claim 1, wherein the grating assembly comprises a plurality of liquid crystal gratings comprising a first substrate, a first electrode, a first liquid crystal layer, a second electrode, and a second substrate disposed in sequence;

the liquid crystal grating comprises a first liquid crystal grating, and a plurality of first electrodes in the first liquid crystal grating extend along a fifth direction;

the refraction device comprises a third substrate, a third electrode, a second liquid crystal layer, a fourth electrode and a fourth substrate which are sequentially arranged; the at least one refractive device comprises a first refractive device in which the third electrode extends in a sixth direction;

And an included angle between the fifth direction and the sixth direction is smaller than or equal to 10 degrees.

20. The display device of claim 1, wherein the at least one refractive device is located on a side of the grating assembly remote from the field lens.

21. A control method based on the display device according to claim 1, comprising:

acquiring a target angle of a position where a target is located;

22. The control method according to claim 21, wherein when the target angle is less than or equal to the threshold angle, the refractive device is controlled to operate in a second operation mode, and the light is deflected as a whole by a second preset angle or not, and the second preset angle is smaller than the first preset angle.

23. The method of claim 21, wherein when the target angle is greater than a threshold angle, controlling the at least one refractive device to operate in the first mode of operation, and deflecting the light as a whole by a first predetermined angle, comprises:

When the target angle is larger than a threshold angle, acquiring the first preset angle according to the target angle;

and controlling at least one refraction device to work in a first working mode, and deflecting the whole light according to the first preset angle.

24. The method of claim 21, wherein when the target angle is greater than a threshold angle, controlling the at least one refractive device to operate in the first operation mode, and after deflecting the light by a first predetermined angle, further comprises:

and acquiring the grating deflection angle of the grating component according to the first preset angle and the target deflection angle.

25. The method according to claim 24, further comprising, after obtaining the grating deflection angle of the grating assembly according to the first preset angle and the target deflection angle:

and keeping the current first preset angle unchanged until the target angle changes.