CN113031257B - a display system - Google Patents

Abstract

A display system, comprising: an array light source, including at least a first sub-array light source, including a plurality of light source units for emitting illumination light; a scanning system, including a central axis of rotation and a plurality of reflective surfaces, the plurality of reflective surfaces rotate around The central axis is rotated to scan the illumination light emitted by the array light source on the incident surface of the spatial light modulator in the form of spot array, so that the display system meets: the first restriction condition—the illumination light distribution of the incident surface of the spatial light modulator It remains constant within one frame display time, and is the same as the second constraint condition—the scanning domain formed on the spatial light modulator by the light source units included in the first sub-array light source through the scanning system; the spatial light modulator projects the The illumination light onto it is modulated to output image light. The invention configures the characteristic parameters of the light source unit by restricting conditions, so that the display system combined with the scanning and spatial light modulator has a wider application range and realizes high contrast.

Description

a display system

technical field

The present invention relates to the field of display technology, in particular to a display system.

Background technique

The existing projection display system in the form of beam scanning utilizes the characteristic of better directivity of the laser, and dynamically changes the direction of the laser beam through the scanning device to form a picture on the screen. This technology can greatly simplify the optical path structure, but it requires high beam collimation, and in order to achieve high resolution, the spot size is required to be very small. Single-mode lasers can realize the above-mentioned characteristics of beams and spots, but single-mode lasers limit the output brightness of projection display systems in the form of beam scanning. Multimode lasers can improve the output brightness of scanning projection equipment, but even if optical shaping devices are added to the optical path of the light source and scanner, the beam collimation and spot size are difficult to achieve the mainstream resolution of the current spatial light modulator.

Therefore, in order to solve the problem that the brightness and resolution of the projection system in the form of beam scanning cannot be achieved at the same time, beam scanning can be performed on the surface of the spatial light modulator.

Spatial light modulators currently used in the projection field include digital micromirror arrays (DMD, Digital Micromirror Device), transmissive liquid crystal light valves (LCD, Liquid Crystal Display), and reflective liquid crystal light valves (LCOS, Liquid Crystal on Silicon).

The digital micromirror array includes a plurality of bistable micromirrors, wherein the bistable state refers to an "on" state and an "off" state. In the "on" state, the light reflected by the micromirrors exits the lens, forming bright pixels on the screen; in the "off" state, the light reflected by the micromirrors enters the absorbing material and does not exit the lens. The micro-mirror can be switched between the "on" and "off" states at a very fast speed (generally, the switching speed can reach the order of microseconds). Different grayscale displays can be realized by controlling the proportion of the micromirror in the "on" state within a frame display time through pulse width modulation (PWM, PulseWidth Modulation). In order to correctly display the gray scale, it is necessary to ensure that the illumination brightness of each pixel surface of the DMD is a constant value at any time within one frame display time

The spatial light modulator using LCD or LCoS controls the refractive index of the liquid crystal by controlling the voltage between the two stages of the liquid crystal to realize different gray scale displays. Therefore, for the liquid crystal spatial light modulator, it is not required that the illumination light of each pixel remains constant within one frame display time.

Compared with LCD and LCoS, DMD has better thermal performance and stability, so it is more widely used in the projection field. However, since the existing beam scanning cannot guarantee a constant illumination on the surface of the spatial light modulator within one frame display time, the method of beam scanning on the surface of the spatial light modulator is not suitable for DMD. This also greatly limits the application of beam scanning in the field of laser projection display.

Contents of the invention

The present invention provides a display system, comprising: an array light source, including at least a first sub-array light source, including a plurality of light source units for emitting illumination light; a scanning system, including a rotating central axis and a plurality of reflecting surfaces, the plurality of reflecting The surface rotates around the central axis of rotation, and is used to scan the illumination light emitted by the array light source on the incident surface of the spatial light modulator in the form of spot array, so that the display system satisfies: the first restriction condition—the The illumination light distribution of the incident surface of the spatial light modulator is kept constant within one frame display time, and the second constraint condition is that each of the light source units included in the first sub-array light source passes through the scanning system in the space The scanning domains formed on the light modulator are the same; the spatial light modulator modulates the illumination light projected by the scanning system to output image light.

In one embodiment, the first sub-array _light source includes x light source units S ₁ , _{S 2 .} The angle γ _i between the central optical axis of L _i and the reference line, the angle between the perpendicular line from the shear point of the scanning cycle of the light beam L _i on the scanning system to the central axis of rotation of the scanning system and the reference line β _i , the brightness angular distribution F _i of the light beam L _i in the scanning direction, wherein the reference line is the vertical line of the incident surface of the spatial light modulator; by setting the light beam L _i emitted by each light source unit S _i The characteristic parameters (γ _i , β _i , F _i ) of , so that the display system satisfies the first constraint condition and the second constraint condition.

In one embodiment, the total light beam composed of the light beams emitted by each of the light source units converges and is incident on the reflective surface of the scanning system.

In one embodiment, at any time within one frame display time, the light spots formed by the light beams emitted by each light source unit on the incident surface of the spatial light modulator are uniformly distributed.

In one embodiment, the angular distributions of the light beams emitted by each of the light source units do not overlap with each other.

In one embodiment, the size of the scan domain in the scan direction is larger than the size of the spatial light modulator in the scan direction.

In one embodiment, a dodging system is also included, and the dodging system is arranged on an optical path between the array light source and the scanning system.

In one embodiment, it further includes a first relay optical system, which is arranged between the dodging system and the scanning system, and is used to assist in adjusting the light beams of each of the light source units so that the display system satisfies the The first constraint and the second constraint.

In one embodiment, it further includes a second relay optical system disposed on the optical path between the scanning system and the spatial light modulator.

In one embodiment, an imaging device is further included, arranged on the outgoing light path of the spatial light modulator, and used for projecting the outgoing light of the spatial light modulator to the screen.

In one embodiment, in the system top view of the display system, the array light source is at least partially coincident with the imaging device, and the first relay optical system is at least partially coincident with the second relay optical system, so The dodging system is at least partially overlapped with the second relay optical system.

In one embodiment, the spatial light modulator is any one of a digital micromirror array, a transmissive liquid crystal light valve, and a reflective liquid crystal light valve.

In one embodiment, the scanning system is any one of a multi-faceted rotating reflective prism, a polygonal truncated scanning device, and a vibrating mirror.

The beneficial effect of the present invention is that, different from the situation of the prior art, the present invention provides a display system, including an array light source, a scanning system, and a spatial light modulator, wherein the light beam emitted by the array light source is incident on the spatial light modulator through the scanning system The incident surface, the present invention limits the scanning characteristics of the incident surface of the spatial light modulator in the scanning system, so that the illumination light on the incident surface of the spatial light modulator has a constant light distribution at any time within one frame display time, and then makes The display system combined with scanning and spatial light modulator can be applied to more technical solutions including DMD spatial light modulator. In addition, by forming the illumination light distribution on the surface of the spatial light modulator, and then using the spatial light modulator to modulate the image light, the power consumption of the light source can be reduced, and the dynamic contrast range can be improved.

Description of drawings

FIG. 1 is a schematic block diagram of a display device according to a preferred embodiment of the present invention.

FIG. 2 is a schematic structural diagram of the first embodiment of the display device shown in FIG. 1 .

FIG. 3 is a schematic diagram of arrangement of array light sources in the first embodiment of the display device of the present invention.

FIG. 4 is a schematic diagram of incident light rays of the multi-faceted rotating reflective prism according to Embodiment 1 of the present invention.

5a, 5b, 5c are schematic diagrams of optical axis distribution and reflected light of the light source unit under different rotation angles.

Figure 6 shows the relationship between rotation angle and illuminance (OA is the reference line).

Fig. 7 is the relationship between the illuminance and time of the central point and the edge point of the spatial light modulator.

Fig. 8 is a top view of the system of Embodiment 1 of the present invention.

FIG. 9 is a schematic diagram of the optical path of Embodiment 2 of the present invention.

Fig. 10 is a schematic diagram of a scanning system according to Embodiment 3 of the invention.

FIG. 11 is a schematic diagram of a scanning system according to Embodiment 4 of the present invention.

Detailed ways

In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

In the following description, many specific details are set forth in order to fully understand the present invention, and the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention.

Please refer to FIGS. 1-2 . FIG. 1 is a schematic block diagram of a display device according to a preferred embodiment of the present invention, and FIG. 2 is a schematic structural view of a first embodiment of the display device according to the present invention. The display device 1 includes an array light source 10 , a scanning system 20 , a spatial light modulator 30 and an imaging device 50 . The array light source 10 includes at least a first sub-array light source, including a plurality of light source units for emitting illumination light, and each light source unit is independently adjustable; the scanning system 20 includes a central axis of rotation and a plurality of reflective surfaces, and the plurality of reflective surfaces Rotating around the central axis of rotation is used to scan the illumination light emitted by the array light source 10 on the surface of the spatial light modulator 30 in the form of a spot array to form an illumination light distribution pattern (which can be realized by adjusting the current of each light source unit); the spatial light The modulator 30 modulates the illumination light projected by the scanning system 20 to output image light; the imaging device 50 is arranged on the outgoing light path of the spatial light modulator 30, and is used to project the outgoing light of the spatial light modulator to Projection screen (not shown).

The core invention of the present invention lies in the requirements for the scanning light beam and the formed scanning pattern on the incident surface of the spatial light modulator 30 . In the present invention, the scanning of the scanning system 20 on the incident surface of the spatial light modulator 30 satisfies the following two conditions: the first restriction condition——the illumination light distribution of the incident surface of the spatial light modulator 30 remains constant within one frame display time ; The second restriction condition—the scanning domains formed by the light source units included in the first sub-array light source on the spatial light modulator through the scanning system are the same.

In the present invention, the array light source may include a plurality of sub-array light sources, and the outgoing light of each sub-array light source is scanned by the incident surface of the spatial light modulator in the scanning system respectively satisfying the first restriction condition and the second restriction condition. It is equivalent to one sub-array light source corresponding to one modulation display area of the spatial light modulator. It can be understood that, in some embodiments, the array light source may also include only one sub-array light source, that is, the first sub-array light source, whose illumination light after being acted by the scanning system covers the entire incident surface of the spatial light modulator. For the convenience of explanation, the technical solution in which the array light source is equivalent to the first sub-array light source is taken as an example below. The technical solution in which the array light source includes multiple sub-array light sources can be obtained by splicing and accumulating the example solutions in space.

Specifically, in this embodiment, the array light source 10 , that is, the first sub-array light source includes m×n light source units, please refer to FIG. 3 , which is a schematic diagram of the arrangement of the array light source in the first embodiment of the display device of the present invention. The array light source 10 includes m rows and n columns of light source units. In this embodiment, the scanning direction of the scanning system 20 is consistent with the "column" direction of the array light source. In other embodiments, the scanning direction of the scanning system 20 can be the same as that of the array light source. The "row" direction remains the same. The light source unit can be a laser diode, a light emitting diode or an organic light emitting diode. In this embodiment, the light source unit is a laser diode. Each light source unit is used to emit an independent lighting beam, and the luminance of each light source unit can be independently controlled.

Different from the previous array light source, the array light source of the present invention is not a combination of light source units emitting parallel light beams with the same or similar angular distribution, but by combining light source units with different luminous characteristic parameters to obtain a display system that can An array light source that satisfies the first restriction and the second restriction.

Specifically, assuming _that the array light source includes x light source units S ₁ , S ₂ ... S _x , the characteristic parameters of the incident beam L _i of any light source unit S _i in the scanning system include: The included angle γ _i of the line, the angle β _i between the vertical line from the shear point of the scanning cycle of the beam L i on the scanning system to the rotation center axis of the scanning system and the reference line β _i , the angular distribution of the brightness of the beam L _i in the scanning direction F _i , where the reference line is the vertical line of the incident surface of the spatial light modulator; by setting the characteristic parameters (γ _i , β _i , F _i ) of _{the light beam L i emitted} by each light source unit S i , so that the display system Satisfy the first and second constraints. In later paragraphs, the relationship between the characteristic parameters (γ _i , β _i , F _i ) and the two constraints will be discussed in more detail.

In the present invention, the scanning cycle shear point refers to the corresponding point on the scanning system when the scanning position of the beam on the target plane changes discontinuously. Before and after the cutting point of the scanning cycle, the angle of the light beam L _i reflected by the scanning system and the corresponding spot position on the spatial light modulator change in a jumping manner. Except for this point, the light beam L _i reflected by the scanning system for continuous change.

The scanning system 20 includes a plurality of reflective surfaces (here understood as at least two reflective surfaces), which are used to scan the illumination light emitted by the light source array 10 on the surface of the spatial light modulator 30 in the form of a light spot, and the above-mentioned scanning cycle cut point Located on the intersection of two adjacent reflective surfaces. In this embodiment, the scanning system 20 is a multi-faceted rotating reflective prism, and the scanning cycle shear point is located on an edge of the multi-faceted rotating reflective prism.

The spatial light modulator 30 modulates the light spot projected thereon by the scanning system 20 to output image light. Preferably, in this embodiment, the spatial light modulator 30 is a DMD, and the DMD includes a plurality of bistable micro-mirrors, wherein the bistable state refers to an "on" state and an "off" state. In the "on" state, the light reflected by the micromirrors exits the lens, forming bright pixels on the screen; in the "off" state, the light reflected by the micromirrors enters the absorbing material and does not exit the lens. The micro-mirror can be switched between the "on" and "off" states at a very fast speed (generally, the switching speed can reach the order of microseconds). Different grayscale displays can be realized by controlling the proportion of the micro-mirror in the "on" state within one frame display time through pulse width modulation (PWM, Pulse Width Modulation). In order to correctly display the gray scale, it is necessary to ensure that the illumination brightness irradiated on the surface of each pixel in the digital micromirror array is a constant value within one frame display time, that is, the illumination light distribution on the incident surface of the spatial light modulator is uniform. The frame display time remains constant. Assuming that the display time of one frame is (0, T), then at any time from 0 to T, the illumination light distribution on the incident surface of the spatial light modulator is the same.

In other embodiments, the spatial light modulator can also be LCD or LCoS. This type of spatial light modulator is an "analog device". By changing the liquid crystal orientation and combining with a polarizer, the light transmittance can be adjusted. Once the liquid crystal orientation adjustment is completed, the light transmittance can be controlled stably.

Please refer to FIG. 4 , which is a schematic diagram of incident light rays of the multi-faceted rotating reflective prism according to Embodiment 1 of the present invention. For example, the multi-faceted rotating reflective prism has N reflective surfaces. At a certain moment, the intersection point of the light L _i scanning system corresponding to the central axis of a light source unit S _i is K, and the K point is located on a certain edge of the multi-faceted rotating reflective prism. , then K point is the scanning cycle shear point. Make a perpendicular line to the rotation central axis of the multi-faceted rotating reflective prism through point K to obtain point O on the rotation central axis. Make the vertical line of the incident surface of the spatial light modulator 30 through point O, obtain the focal point A of the spatial light modulator 30, define OA as a reference line, and the angle of the line coincident with OA is 0 °, and the multi-faceted rotating reflective prism counterclockwise Rotation is defined as "positive" and clockwise rotation is defined as "negative". As shown in the figure, taking point O as the origin of the coordinate axis, β _i in the figure is a positive value, γ _i is a positive value, and h _i is a positive value; if h _i is below the OA line, it is a negative value (mathematically , in a non-physical sense). Suppose the length of OK is R, then h _i =Rsinβ _i .

It can be calculated that the angle range of any light L _i reflected by the scanning system is in That is, the scanning angle range of the light beam L _i .

Assuming that the length of the OA line segment is D, the scanning range of the outgoing light corresponding to the light beam L _i on the spatial light modulator 30 can be expressed as H _i1 ˜H _i2 :

Wherein H _i1 and H _i2 are the coordinate values of the light beam L _i on the incident surface of the spatial light modulator 30 in the scanning direction, which can be negative values (as shown below point A as shown in the figure) or positive values (as shown in A as shown in the figure). point above).

In the present invention, after the array light source 10 is reflected by the multi-faceted rotating reflective prism, the illumination brightness of each pixel projected onto the surface of the spatial light modulator is a constant value, for any L _i , H _i1 =a, H _i2 =b, where a and b are constants, that is, the scanning fields formed by each light beam on the spatial light modulator are the same.

The illumination brightness of each pixel surface of the spatial light modulator is a constant value at any moment within a frame display time. Assuming that the central axis of each light source unit corresponds to the intersection point of light passing through the reflective surface of the multi-faceted rotating reflective prism on the spatial light modulator is p _i (xi _, y _i ), where _xi is the surface of the spatial light modulator in the scanning direction The position coordinates of y _i are the position coordinates on the surface of the spatial light modulator orthogonal to the scanning dimension, then the illumination brightness F of a certain point on the surface of the spatial light modulator can be expressed as:

and

F=c

Among them, c is a constant and is determined by the image signal. Generally speaking, since the spatial light modulator can only perform "light reduction" processing, the selection of c is not lower than the brightness of the corresponding image area; P is a certain moment for p _i ( _xi , y _i ) The number of light source units that contribute to the point.

Therefore, after knowing the number of rows and columns of the array light source, the size of the multi-faceted rotating reflective prism, and the number of reflecting surfaces of the multi-faceted rotating reflective prism, the characteristic parameters of the light source unit can be obtained through the above formulas (1)(2)(3).

In a preferred embodiment of the present invention, at any time within one frame display time, the light spots formed by the light beams emitted by each light source unit on the incident surface of the spatial light modulator are uniformly distributed, that is, the light spots along the scanning direction The distance distribution is uniform, and the size distribution of each spot is uniform. This makes it possible to reduce the influence between adjacent light spots and reduce the computational complexity of adjusting the light source during the scanning of the light spots.

According to the obtained optimal array light source characteristics, a simulation is performed to verify whether a stable light distribution can be formed on the spatial light modulator. In this embodiment, a uniform white field is used as a preset pattern. Please refer to FIGS. 5 a , 5 b , and 5 c , which are schematic diagrams of optical axis distribution and reflected light of the light source unit under different rotation angles. In the figure, there are 16 light source units in the scanning direction (the light beams from 1-16 light source units are respectively clockwise in the figure, and only the most edge beams 1 and 16 are marked), and the multi-faceted rotating reflective prism has 16 reflective surfaces , Figure 5a is defined as a schematic diagram of the optical axis distribution and reflected light of the light source unit when rotating 0°, Figure 5b is a schematic diagram of the optical axis distribution and reflected light of the light source unit when rotating 5°, and Figure 5c is the optical axis of the light source unit when rotating 10° Schematic diagram of distribution and reflection of light. With the rotation of the multi-faceted rotating reflective prism, the total coverage of the light irradiated on the spatial light modulator does not change significantly, but the coverage of each beam is moving in a circular manner. As shown in the figure, beam 1 is in the spatial light The light spot 1 on the modulator moves to the right gradually with the rotation of the multi-faceted rotating reflective prism, while the light spots formed by the beams of other light sources on the spatial light modulator also move to the right. Left end, then move to the right.

In this embodiment, the total light beam composed of the light beams emitted by each light source unit converges and is incident on the reflective surface of the scanning system. The "convergence" here does not refer to the convergence of a single beam, but the convergence of multiple beams (such as 16 beams in the figure), so that the distance between the beams is reduced. This technical solution is different from the array light source emitting in parallel, and can realize the first and second limiting conditions of the display system of the present invention, especially enabling the light beam to form a cyclically stable illumination light distribution after passing through the scanning system.

In this embodiment, the angular distributions of the light beams emitted by each light source unit do not overlap with each other, otherwise two adjacent light beams may overlap too much on the spatial light modulator, resulting in the inability to achieve higher precision illumination light distribution modulation .

Please refer to Figure 6. Figure 6 shows the relationship between the position of the spatial light modulator and the illuminance (OA is the reference line). It can be seen that the light distribution in the large middle area is relatively uniform, while the illuminance distribution at the edge positions fluctuates greatly. Roughly corresponds to the size covered by a light spot of a light beam on the spatial light modulator along the scanning direction, the area with large fluctuations is not conducive to light distribution modulation, and may cause the edge area to be dark, so this area should be reduced as much as possible. In the present invention, the size of the edge area can be reduced by increasing the number of light source units of the array light source while reducing the beam spot.

Please refer to FIG. 7 . FIG. 7 shows the relationship between illuminance and time at the central point and the edge point of the spatial light modulator. It can be seen that the illumination spot will move with a spatial cycle as the scanning angle changes, and the non-uniformity of the edge will cause the light at the edge to be unusable, while the non-edge point of the spatial light modulator can maintain uniformity in space and time sex. Therefore preferably, the size of the scanning domain of the light source unit in the scanning direction can be larger than the size of the spatial light modulator in the scanning direction, so that the illumination light on the surface of the spatial light modulator can be kept stable, or more light source units can be introduced , can reduce light loss at the edge and improve light efficiency.

The display system 1 may further include a uniform light system 60 , a first relay optical system 70 , and a second relay optical system 80 . The dodging system 60 is set on the light path between the array light source and the scanning system, and shapes and dodges the illumination light emitted by the light source unit to generate a light spot adapted to the scanning system 20 . The first relay optical system 70 is arranged between the uniform light system 60 and the scanning system 20, and may include optical devices such as reflective mirrors, free-form surface lenses, or reflective mirrors, and can be used to assist in adjusting the light beam of the light source unit so that the display system meets the requirements. the first constraint and the second constraint. The second relay optical system 80 is arranged on the optical path between the scanning system and the spatial light modulator, and is used for shaping the light spot emitted from the scanning system 20 to uniformly illuminate the spatial light modulator 30 .

Please refer to FIG. 8. FIG. 8 is a top view of the system according to Embodiment 1 of the present invention, wherein the imaging system 50 is at least partially overlapped with the array light source 10, the first relay optical system 70 is at least partially overlapped with the second relay optical system 80, and the light is uniform. The system 60 is at least partially overlapped with the second relay optical system 80 , and the compactness of the display device can be ensured through the overlapping arrangement.

The present invention obtains the optimal arrangement of the light source array by calculating the characteristic parameters of the light source unit, so that the illumination brightness of each pixel surface of the spatial light modulator is a constant value at any time within one frame display time, and then obtains the optimal arrangement of the light source array. DMD's beam scanning display system.

Please refer to FIG. 9 , which is a schematic diagram of an optical path according to Embodiment 2 of the present invention. Embodiment 2 of the present invention differs from Embodiment 1 only in that the scanning system scans in the horizontal direction, and the incident light and outgoing light are separated in horizontal space to leave enough space for optical devices such as the relay optical system. For the calculation of the characteristic parameters of the light beam of the light source unit, reference may be made to Embodiment 1.

Please refer to FIG. 10 , which is a schematic diagram of a scanning system according to Embodiment 3 of the invention. Different from Embodiment 1, the scanning system in Embodiment 3 of the present invention uses a polygonal truncated scanning device. Compared with the above technical solution, this technical solution only adds a fixed displacement in the vertical direction. For the calculation of the characteristic parameters of the light beam of the light source unit, reference may be made to Embodiment 1.

Please refer to FIG. 11 , which is a schematic diagram of a scanning system according to Embodiment 4 of the present invention. Different from Embodiment 1, the scanning system in Embodiment 4 of the present invention uses a vibrating mirror. Embodiment 1 of the present invention adopts a multi-faceted rotating reflective prism, and the scanning angle of the outgoing light can be expressed as 4π/N, where N is the number of reflecting surfaces of the multi-faceted rotating reflective prism. In order to avoid the distortion of the scanning area of the light source unit, the scanning angle is required to be reduced, so the number of reflecting surfaces of the multi-faceted rotating reflective prism needs to be increased, which increases the radius of the multi-faceted rotating reflective prism, and the processing difficulty is greatly increased. The use of two mirrors at an angle of θ to form a vibrating mirror, and reciprocating rotation around the rotation center can solve the disadvantage of difficult processing of multi-faceted rotating reflective prisms. The scan angle range of the galvanometer is twice the rotation angle, and the scan angle can be reduced by increasing the θ angle and increasing the distance between the rotation center and the mirror. If the rotation angle is too small, each spot cannot traverse all positions; if the rotation angle is too large, the total illumination spot will move greatly, and the uniformity of the illumination spot on the spatial light modulator along time and space cannot be guaranteed . For the calculation of the characteristic parameters of the light source unit, reference may be made to Embodiment 1. The galvanometer can be regarded as the two reflective surfaces of the multi-faceted rotating reflective prism in Embodiment 1, the circumcircle can be the center of rotation, and the intersection of the intersection line of the two mirrors and the light beam is the scanning cycle shear point.

It will be apparent to those skilled in the art that the invention is not limited to the details of the above-described exemplary embodiments, but that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Accordingly, the embodiments should be regarded in all points of view as exemplary and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the invention be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned. In addition, it is obvious that the word "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. Multiple units or devices stated in the device claims may also be realized by the same unit or device through software or hardware.

The above is only the embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process conversion made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technologies fields, are all included in the scope of patent protection of the present invention in the same way.

Claims (13)

1. A display system, comprising:

an array light source including at least a first sub-array light source including a plurality of light source units for emitting illumination light;

the scanning system comprises a rotation center shaft and a plurality of reflecting surfaces, wherein the reflecting surfaces rotate around the rotation center shaft and are used for scanning illumination light emitted by the array light source on an incidence surface of the spatial light modulator in a light spot array mode, so that the display system meets the following requirements: a first constraint that an illumination light distribution of an incident surface of the spatial light modulator is kept constant for one frame of display time, and a second constraint that each of the light source units included in the first sub-array light sources is the same as a scanning field formed on the spatial light modulator by the scanning system;

the spatial light modulator modulates the illumination light projected thereto by the scanning system, and outputs image light.

2. The display system of claim 1, wherein the first sub-array light source comprises x light source units S ₁ ，S ₂ ……S _x Any one of the light source units S _i Incident light beam l at the scanning system _i The characteristic parameters of (a) include: light beam l _i Included angle gamma between the central optical axis of (C) and the reference line _i Beam l _i An angle beta between a perpendicular line from a scanning cycle shear point on the scanning system to a rotation center axis of the scanning system and the reference line _i Beam L _i Luminance angular distribution F in the scanning direction _i Wherein the reference line is a perpendicular to the incidence plane of the spatial light modulator;

by setting each light source unit S _i Emitted light beam L _i Characteristic parameter (gamma) _i ，β _i ，F _i ) Such that the display system satisfies the first and second constraints.

3. The display system according to claim 2, wherein a total light beam composed of light beams emitted from the respective light source units is converged and incident on the reflecting surface of the scanning system.

4. The display system according to claim 2, wherein light spots formed on the incidence surface of the spatial light modulator by the light beams emitted from the respective light source units are uniformly distributed at any one time within one frame of display time.

5. The display system according to claim 2, wherein the angular distributions of the light beams emitted by the light source units do not overlap each other.

6. The display system of claim 1, wherein a dimension of the scan field in a scan direction is greater than a dimension of the spatial light modulator in a scan direction.

7. The display system of claim 1, further comprising a dodging system disposed in an optical path between the array light source and the scanning system.

8. The display system of claim 7, further comprising a first relay optical system disposed between the dodging system and the scanning system for assisting in adjusting the light beam of each of the light source units such that the display system satisfies the first constraint and the second constraint.

9. The display system of claim 8, further comprising a second relay optical system disposed in an optical path between the scanning system and the spatial light modulator.

10. The display system according to any one of claims 1 to 9, further comprising an imaging device provided on an outgoing light path of the spatial light modulator to project outgoing light of the spatial light modulator to a screen.

11. The display system of claim 9, wherein the array light source is at least partially coincident with the imaging device, the first relay optical system is at least partially coincident with the second relay optical system, and the dodging system is at least partially coincident with the second relay optical system in a system top view of the display system.

12. The display system of claim 1, wherein the spatial light modulator is any one of a digital micromirror array, a transmissive liquid crystal light valve, and a reflective liquid crystal light valve.

13. The display system of claim 1, wherein the scanning system is any one of a polygon mirror, a polygon mesa scanning device, and a galvanometer.