CN113031257B - Display system - Google Patents

Display system Download PDF

Info

Publication number
CN113031257B
CN113031257B CN201911247601.1A CN201911247601A CN113031257B CN 113031257 B CN113031257 B CN 113031257B CN 201911247601 A CN201911247601 A CN 201911247601A CN 113031257 B CN113031257 B CN 113031257B
Authority
CN
China
Prior art keywords
light
light source
scanning
array
display system
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201911247601.1A
Other languages
Chinese (zh)
Other versions
CN113031257A (en
Inventor
余新
胡飞
吴超
李屹
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shenzhen Appotronics Corp Ltd
Original Assignee
Appotronics Corp Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Appotronics Corp Ltd filed Critical Appotronics Corp Ltd
Priority to CN201911247601.1A priority Critical patent/CN113031257B/en
Priority to PCT/CN2020/126546 priority patent/WO2021114966A1/en
Publication of CN113031257A publication Critical patent/CN113031257A/en
Application granted granted Critical
Publication of CN113031257B publication Critical patent/CN113031257B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/10—Scanning systems
    • G02B26/12—Scanning systems using multifaceted mirrors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/18—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for optical projection, e.g. combination of mirror and condenser and objective
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/005—Projectors using an electronic spatial light modulator but not peculiar thereto
    • G03B21/006—Projectors using an electronic spatial light modulator but not peculiar thereto using LCD's
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/005—Projectors using an electronic spatial light modulator but not peculiar thereto
    • G03B21/008—Projectors using an electronic spatial light modulator but not peculiar thereto using micromirror devices
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details
    • G03B21/20—Lamp housings

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Mechanical Optical Scanning Systems (AREA)

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; 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 the incidence surface of the spatial light modulator in a light spot array mode, so that the display system meets the following requirements: the first constraint condition that the illumination light distribution of the incident surface of the spatial light modulator is kept constant for one frame of display time, and the second constraint condition that each light source unit included in the first sub-array light source is the same as a scanning field formed on the spatial light modulator by the scanning system; and a spatial light modulator for modulating illumination light projected onto the spatial light modulator by the scanning system and outputting image light. The application configures the characteristic parameters of the light source unit by limiting conditions, so that the display system combined with the scanning and spatial light modulator has wider application range and realizes high contrast ratio.

Description

Display system
Technical Field
The application relates to the technical field of display, in particular to a display system.
Background
The existing projection display system with the beam scanning mode utilizes the characteristic of better directivity of laser, dynamically changes the direction of the laser beam through a scanning device, and forms a picture on a screen. The technology can greatly simplify the light path structure, but has high requirements on the beam collimation, and in order to realize high resolution, the light spot size is required to be very small. Single mode lasers enable the beam and spot to achieve the above characteristics, 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 devices, but even if optical shaping devices are added in the light paths of the light source and the scanner, the beam collimation and the spot size are difficult to reach 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 beam scanning form cannot be simultaneously achieved, the beam scanning can be performed on the surface of the spatial light modulator.
Spatial light modulators currently used in projection applications include digital micromirror arrays (DMD, digital Micromirror Device), transmissive liquid crystal light valves (LCD, liquid Crystal Display), reflective liquid crystal light valves (LCOS, liquid Crystal on Silicon).
The digital micromirror array comprises a plurality of bistable micromirrors, wherein bistable states refer to "on" and "off states. In the "on" state, light reflected by the micro-mirror exits from the lens, forming bright pixels on the screen; in the "off" state, light reflected by the micro-mirrors is incident on the absorbing material and does not exit the lens. The micromirror can be switched in "on" and "off states at a very fast speed (typically a switching speed on the order of a subtle can be achieved). Different gray scale displays can be realized by controlling the duty ratio of the micro-mirror in an 'on' state in one frame of display time through pulse width modulation (PWM, pulse Width Modulation). In order to correctly display gray scale, it is necessary to ensure that the brightness of illumination light on each pixel surface of the DMD is constant at any time within a frame display time
And the spatial light modulator adopting LCD or LCoS controls the refractive index of the liquid crystal by controlling the voltage of two stages of the liquid crystal, so as to realize different gray scale display. Thus, for a liquid crystal spatial light modulator, the illumination light of each pixel is not required to remain constant for one frame of display time.
DMD has better thermal performance and stability than LCD and LCoS, and therefore has wider application in projection. However, the conventional beam scanning cannot ensure that a constant illumination is formed on the surface of the spatial light modulator during one frame of display time, and thus the method of performing beam scanning on the surface of the spatial light modulator is not suitable for the DMD. This also greatly limits the application of beam scanning in the field of laser projection displays.
Disclosure of Invention
The present application provides a display system including: 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.
In one embodiment, 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.
In one embodiment, a total light beam formed by the light beams emitted by the light source units is converged and incident on the reflecting surface of the scanning system.
In one embodiment, at any time in a frame display time, light spots formed on the incident surface of the spatial light modulator by the light beams emitted by the light source units are uniformly distributed.
In one embodiment, the angular distributions of the light beams emitted by the light source units do not overlap each other.
In one embodiment, the size of the scan field in the scan direction is greater than the size of the spatial light modulator in the scan direction.
In one embodiment, the system further comprises a dodging system, wherein the dodging system is arranged on an optical path between the array light source and the scanning system.
In one embodiment, the display system further includes 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 so that the display system satisfies the first constraint condition and the second constraint condition.
In one embodiment, the optical system further includes a second relay optical system disposed on an optical path between the scanning system and the spatial light modulator.
In one embodiment, the display device further comprises an imaging device, which is arranged on the emergent light path of the spatial light modulator and used for projecting the emergent light of the spatial light modulator to a screen.
In one embodiment, in a system top view of the display system, the array light source is at least partially overlapped with the imaging device, the first relay optical system is at least partially overlapped with the second relay optical system, and 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 polygon rotary reflecting prism, a polygon stage type scanning device and a galvanometer.
The application has the beneficial effects that the application is different from the prior art, and provides a display system which comprises an array light source, a scanning system and a spatial light modulator, wherein light beams emitted by the array light source are incident on the incidence surface of the spatial light modulator through the scanning system. In addition, by forming illumination light distribution on the surface of the spatial light modulator and modulating image light by the spatial light modulator, power consumption of the light source can be reduced and dynamic contrast range can be improved.
Drawings
Fig. 1 is a block diagram of a display device according to a preferred embodiment of the application.
Fig. 2 is a schematic diagram showing a specific structure of a first embodiment of the display device shown in fig. 1.
Fig. 3 is a schematic diagram of an array light source arrangement of a first embodiment of a display device according to the present application.
Fig. 4 is a schematic view of incident light of a polygon mirror according to a first embodiment of the present application.
Fig. 5a, 5b, 5c are schematic diagrams of optical axis distribution and reflected light of the light source unit at different rotation angles.
Fig. 6 shows the relationship between rotation angle and illuminance (OA is a reference line).
FIG. 7 is a graph of illumination versus time for center and edge points of a spatial light modulator.
Fig. 8 is a top view of the system of embodiment 1 of the present application.
Fig. 9 is a schematic view of an optical path of embodiment 2 of the present application.
Fig. 10 is a schematic diagram of a scanning system according to embodiment 3 of the present application.
Fig. 11 is a schematic diagram of a scanning system according to embodiment 4 of the present application.
Detailed Description
In order that the above-recited objects, features and advantages of the present application will be more clearly understood, a more particular description of the application will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It should be noted that, without conflict, the embodiments of the present application and features in the embodiments may be combined with each other.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, and the described embodiments are merely some, rather than all, embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
Referring to fig. 1-2, fig. 1 is a schematic block diagram of a display device according to a preferred embodiment of the application, and fig. 2 is a schematic block diagram of a first embodiment of the display device according to the application. The display device 1 comprises an array light source 10, a scanning system 20, a spatial light modulator 30 and an imaging device 50. An array light source 10, at least comprising a first sub-array light source, comprising a plurality of light source units for emitting illumination light, each light source unit being independently adjustable; a scanning system 20 including a rotation center axis and a plurality of reflecting surfaces rotating around the rotation center axis for scanning illumination light emitted from 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 achieved by adjusting the current of each light source unit); a spatial light modulator 30 for modulating illumination light projected thereto by the scanning system 20 and outputting image light; an imaging device 50 disposed on the outgoing light path of the spatial light modulator 30 for projecting the outgoing light of the spatial light modulator onto a projection screen (not shown).
The core point of the present application is the requirement for a scanning beam and a formed scanning pattern on the incident surface of the spatial light modulator 30. In the present application, the scanning of the scanning system 20 on the incident surface of the spatial light modulator 30 satisfies the following two conditions: the first constraint, that is, the illumination light distribution of the incident surface of the spatial light modulator 30 remains constant for one frame of display time; a second limitation is that each of the light source units included in the first sub-array light source is identical in scanning field formed on the spatial light modulator by the scanning system.
In the present application, the array light source may include a plurality of sub-array light sources, and the outgoing light of each sub-array light source satisfies the first constraint condition and the second constraint condition, respectively, through scanning of the incident surface of the spatial light modulator in the scanning system, respectively. Corresponding to a modulated display area of a sub-array light source corresponding to the spatial light modulator. It will be appreciated that in some embodiments, the array light source may also include only one sub-array light source, i.e., the first sub-array light source, which is illuminated by the scanning system to cover the entire entrance face of the spatial light modulator. For convenience of explanation, the technical scheme that the array light source is equivalent to the first sub-array light source is taken as an example for explanation, and the technical scheme that the array light source comprises a plurality of sub-array light sources can be obtained by performing space splicing and accumulation on the example scheme.
Specifically, in the present embodiment, the array light source 10, i.e. the first sub-array light source, includes m×n light source units, please refer to fig. 3, fig. 3 is a schematic diagram of an array light source arrangement of a first embodiment of the display device of the present application. The array light source 10 includes m rows and n columns of light source units, and in this embodiment, the scanning direction of the scanning system 20 is consistent with the "column" direction of the array light source, and in other embodiments, the scanning direction of the scanning system 20 may be consistent with the "row" direction of the array light source. The light source unit may 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 for emitting independent illumination light beams, and the luminous brightness of each light source unit can be independently controlled.
Unlike the conventional array light source, the array light source of the present application does not emit a combination of light source units of parallel light beams having the same or similar angular distribution, but combines light source units having different light emission characteristic parameters, thereby obtaining an array light source capable of enabling the display system to satisfy the first constraint condition and the second constraint condition.
Specifically, it is assumed that the array light source includes x light source units S 1 ，S 2 ……S x Any one of the light source units S i Incident light beam L on 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 Scanning cycle shear point on scanning system to scanning systemIncluded angle beta between perpendicular line of rotation center axis and reference line i Beam L i Luminance angular distribution F in the scanning direction i Wherein the reference line is a perpendicular to the plane of incidence 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 ) So that the display system satisfies the first constraint and the second constraint. In a later paragraph, the characteristic parameter (γ i ，β i ，F i ) The relationship to the two constraints is discussed in more detail.
In the present application, a scan cycle shear point refers to a point on the scanning system corresponding to when the scan position of the light beam on the target plane discontinuously changes. Before and after the scanning cycle shear point, the light beam L i The angle of the beam reflected by the scanning system and the position of the spot corresponding to the spatial light modulator are changed in a jump manner, except for the spot, the beam L i The light beam reflected by the scanning system is continuously changed.
The scanning system 20 comprises a plurality of reflecting surfaces (here understood as at least two reflecting surfaces) for scanning illumination light emitted by the light source array 10 across the surface of the spatial light modulator 30 in the form of light spots, the above-mentioned scanning cycle shear points being located on the intersection of two adjacent reflecting surfaces. In this embodiment, the scanning system 20 is a polygon mirror, and the scanning cycle shear point is located on the edge of the polygon mirror.
The spatial light modulator 30 modulates a light spot projected thereto by the scanning system 20, and outputs image light. Preferably, in this embodiment, the spatial light modulator 30 is a DMD that includes a plurality of bi-stable micro-mirrors, wherein the bi-stable states refer to an "on" state and an "off" state. In the "on" state, light reflected by the micro-mirror exits from the lens, forming bright pixels on the screen; in the "off" state, light reflected by the micro-mirrors is incident on the absorbing material and does not exit the lens. The micromirror can be switched in "on" and "off states at a very fast speed (typically a switching speed on the order of a subtle can be achieved). Different gray scale displays can be realized by controlling the duty ratio of the micro-mirror in an 'on' state in one frame of display time through pulse width modulation (PWM, pulse Width Modulation). In order to correctly display gray scales, it is necessary to ensure that the brightness of illumination light illuminating the surface of each pixel in the dmd is constant during a frame of display time, that is, the distribution of illumination light on the incident surface of the spatial light modulator is kept constant during a frame of display time. When the display time of one frame is set to be (0, T), the illumination light distribution on the incidence plane of the spatial light modulator is the same at any time of 0 to T.
In other embodiments, the spatial light modulator may also be an LCD or LCoS. The spatial light modulator is an analog device, and can realize the adjustment of the light transmittance by changing the liquid crystal orientation and combining with an analyzer, and once the liquid crystal orientation adjustment is completed, the light transmittance can be stably controlled.
Referring to fig. 4, fig. 4 is a schematic view of incident light of a polygon mirror according to a first embodiment of the application. For example, the polygon rotary reflecting prism has N reflecting surfaces, and at a certain moment, a light source unit S i Light ray L corresponding to the central axis of (2) i The intersection point of the scanning system is K, and the K point is positioned on one edge of the polygon rotary reflecting prism, and then the K point is a scanning cycle shear point. And (5) making a perpendicular line to the rotation central axis of the polygon rotary reflecting prism through the K point to obtain an O point on the rotation central axis. The O point is taken as a perpendicular to the incident surface of the spatial light modulator 30, a focal point a with respect to the spatial light modulator 30 is obtained, OA is defined as a reference line, the angle of the line overlapping with OA is 0 °, the counterclockwise rotation of the polygon rotary reflecting prism is defined as "positive", and the clockwise rotation is defined as "negative". As shown in the figure, with the point O as the origin of the coordinate axis, beta in the figure i Positive value, gamma i Positive value, h i Positive values; if h i Below the OA line, a negative value (mathematically, not physically). Let OK length be R, then h i ＝Rsinβ i 。
Can be calculated to obtain any light L i The angle range after being reflected by the scanning system isWherein the method comprises the steps ofI.e. beam L i Is provided.
Assuming the length of the OA line segment is D, the light beam L i The scan range of the corresponding outgoing light ray on the spatial light modulator 30 can be expressed as H i1 ～H i2 ：
Wherein H is i1 、H i2 Is a light beam L i The coordinate value of the incident surface of the spatial light modulator 30 in the scanning direction may be a negative value (as shown below the point a) or a positive value (as shown above the point a).
In the present application, in order to make the brightness of illumination light projected to each pixel point of the surface of the spatial light modulator be a constant value after the array light source 10 is reflected by the polygon rotary reflection prism, for any L i ，H i1 ＝a，H i2 And b, wherein a and b are constants, i.e. the scan fields formed by the beams on the spatial light modulator are identical.
The illumination brightness of each pixel surface of the spatial light modulator is constant at any time within a frame display time. Assuming that the intersection point of the light rays corresponding to the central axis of each light source unit and passing through the reflecting surface of the multi-surface rotary reflecting prism on the spatial light modulator is p i (x i ,y i ) Wherein x is i Y is the position coordinate on the surface of the spatial light modulator in the scanning direction i For position coordinates on the surface of the spatial light modulator in the scan dimension orthogonal thereto, the illumination intensity F at a point on the surface of the spatial light modulator can be expressed as:
and is also provided with
F＝c
Wherein c is constant and is determined by the image signal, and in general, c is selected to be not lower than the brightness of the corresponding image area because the spatial light modulator can only perform the dimming process; p is a time P i (x i ,y i ) The number of light source units contributed by the dots.
Therefore, after knowing the number of rows and columns of the array light source, the size of the polygon rotary reflecting prism and the number of reflecting surfaces of the polygon rotary reflecting prism, the characteristic parameters of the light source unit can be obtained through the formulas (1), (2) and (3).
In a preferred embodiment of the present application, at any time in a frame display time, light spots formed on the incident surface of the spatial light modulator by the light beams emitted from the light source units are uniformly distributed, that is, the distance of each light spot in the scanning direction is uniformly distributed, and the size distribution of each light spot is uniform. Thus, the influence between adjacent light spots can be reduced, and the operation complexity of light source adjustment in the light spot scanning process is reduced.
According to the optimal array light source characteristics obtained by solving, simulation is performed to verify whether stable light distribution can be formed on the spatial light modulator, and in the embodiment, a uniform white field is used as a preset pattern. Fig. 5a, 5b, and 5c are schematic diagrams showing the distribution of the optical axes of the light source units and the reflected light under different rotation angles. The figure comprises 16 light source units (light beams emitted by 1-16 light source units in clockwise direction in the figure are marked only by the light beams 1 and 16 at the extreme edges), a multi-surface rotary reflecting prism is adopted and provided with 16 reflecting surfaces, the figure 5a is defined as an optical axis distribution and reflected light ray schematic diagram of the light source units when rotating by 0 degrees, the figure 5b is an optical axis distribution and reflected light ray schematic diagram of the light source units when rotating by 5 degrees, and the figure 5c is an optical axis distribution and reflected light ray schematic diagram of the light source units when rotating by 10 degrees. The total coverage of the light irradiated on the spatial light modulator does not change significantly along with the rotation of the polygon mirror, and the coverage of each light beam moves circularly, as shown in the figure, the light spot 1 of the light beam 1 on the spatial light modulator gradually moves to the right along with the rotation of the polygon mirror, and the light spots formed by the light beams of other light sources on the spatial light modulator also move to the right, and when the light spots move to the edge, the light spots return to the leftmost end and then move to the right.
In this embodiment, the total light beam composed of the light beams emitted from the light source units is converged and incident on the reflecting surface of the scanning system. The term "converging" herein does not refer to the convergence of a single light beam, but rather, converges a plurality of light beams (16 light beams in the drawing) such that the interval between the light beams is reduced. The technical scheme is different from the parallel emergent array light source, the first limiting condition and the second limiting condition of the display system can be realized, and particularly, the light beam can form circularly stable illumination light distribution after passing through the scanning system.
In this embodiment, the angular distributions of the light beams emitted from the light source units do not overlap each other, which may cause too many overlapping areas of adjacent two light beams on the spatial light modulator, resulting in failure to achieve higher-precision illumination light distribution modulation.
Referring to fig. 6, fig. 6 shows the relationship between the position of the spatial light modulator and the illuminance (OA is a reference line), it can be seen that the light distribution in the middle larger region is relatively uniform, and the illuminance distribution at the edge position fluctuates greatly, which corresponds to the size of a light spot of one light beam covered by the spatial light modulator along the scanning direction, and the region with the large fluctuation is unfavorable for the light distribution modulation, which may cause the edge region to be dark, so that the region is reduced as much as possible. In the present application, the edge area size can be reduced by increasing the number of light source units of the array light source while reducing the beam spot.
Referring to fig. 7, fig. 7 shows the relationship between the illumination of the center point and the edge point of the spatial light modulator and time. It can be seen that the illumination spot will have a spatial period of movement with the angular change of the scan, the non-uniformity of the edges will result in the light at the edges not being used, while the non-edge points of the spatial light modulator may remain spatially and temporally uniform. Therefore, the scanning area of the light source unit can be made to be larger than the scanning area of the spatial light modulator in the scanning direction, so that illumination light on the surface of the spatial light modulator can be kept stable, or more light source units can be introduced, light loss at the edge can be reduced, and light efficiency is improved.
The display system 1 may further include a dodging system 60, a first relay optical system 70, and a second relay optical system 80. The dodging system 60 is disposed on the light path between the array light source and the scanning system, and shapes and dodges the illumination light emitted from the light source unit to generate a light spot adapted to the scanning system 20. The first relay optical system 70, disposed between the dodging system 60 and the scanning system 20, may include optical devices such as a reflective mirror, a free-form surface lens, or a reflective mirror, and may be used to assist in adjusting the light beam of the light source unit so that the display system satisfies the first constraint condition and the second constraint condition. The second relay optical system 80 is disposed 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.
Referring to fig. 8, fig. 8 is a top view of a system in embodiment 1 of the present application, wherein the imaging system 50 at least partially overlaps the array light source 10, the first relay optical system 70 at least partially overlaps the second relay optical system 80, and the dodging system 60 at least partially overlaps the second relay optical system 80, so that the compactness of the display device can be ensured by overlapping the two relay optical systems.
According to the application, the characteristic parameters of the light source units are calculated, so that the optimal arrangement of the light source arrays is obtained, the illumination brightness of each pixel surface of the spatial light modulator is a constant value at any time within one frame of display time, and a light beam scanning display system suitable for the DMD is obtained.
Referring to fig. 9, fig. 9 is a schematic diagram of an optical path of embodiment 2 of the present application. Embodiment 2 of the present application differs from embodiment 1 only in that the scanning system scans in the horizontal direction, and the incident light and the outgoing light are separated in the horizontal space to leave a sufficient space to accommodate optical devices such as a relay optical system. The solution of the characteristic parameters of the light beam of the light source unit can be referred to embodiment 1.
Referring to fig. 10, fig. 10 is a schematic diagram of a scanning system according to embodiment 3 of the application. Unlike embodiment 1, the scanning system in embodiment 3 of the present application employs a polygon stage type scanning device, and this technical solution is only increased by a fixed displacement in the vertical direction compared to the above technical solution. The solution of the characteristic parameters of the light beam of the light source unit can be referred to embodiment 1.
Referring to fig. 11, fig. 11 is a schematic diagram of a scanning system according to embodiment 4 of the present application. Unlike example 1, the scanning system of example 4 of the present application employs a galvanometer. In the embodiment 1 of the application, a multi-face rotary reflecting prism is adopted, and the angle of emergent ray scanning can be expressed as 4pi/N, wherein N is the number of reflecting surfaces of the multi-face rotary reflecting prism. In order to avoid distortion of the scanning field of the light source unit, the scanning angle is required to be reduced, and thus the number of reflecting surfaces of the polygon mirror needs to be increased, which increases the radius of the polygon mirror, and the processing difficulty is greatly increased. And two mirrors forming an included angle theta are adopted to form a vibrating mirror, and the vibrating mirror performs reciprocating rotary motion around a rotary center, so that the defect of high processing difficulty of the multi-face rotary reflecting prism can be overcome. The scanning angle range of the galvanometer is twice the rotation angle, and the scanning angle can be reduced by increasing the size of the angle theta and increasing the distance between the rotation center and the reflecting mirror. If the rotation angle is too small, each spot cannot traverse all positions; if the rotation angle is too large, the total illumination light spot can move greatly, and the uniformity of the illumination light spot on the spatial light modulator along time and space cannot be ensured. The solution of the characteristic parameters of the light source unit can be referred to embodiment 1. The vibrating mirror can be regarded as two reflecting surfaces of the polygon rotary reflecting prism in the embodiment 1, the circumscribed circle can take the rotation center as the circle center, and the intersection point of the intersection line of the two mirrors and the light beam is the scanning cycle shear point.
It will be evident to those skilled in the art that the application is not limited to the details of the foregoing illustrative embodiments, and that the present application may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned. Furthermore, it is evident that the word "comprising" does not exclude other elements or steps, and that the singular does not exclude a plurality. Several of the units or means recited in the apparatus claims may also be embodied by one and the same unit or means, either in software or hardware.
The foregoing description is only of embodiments of the present application, and is not intended to limit the scope of the application, and all equivalent structures or equivalent processes using the descriptions and the drawings of the present application or directly or indirectly applied to other related technical fields are included in the scope of the present application.

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.
CN201911247601.1A 2019-12-09 2019-12-09 Display system Active CN113031257B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN201911247601.1A CN113031257B (en) 2019-12-09 2019-12-09 Display system
PCT/CN2020/126546 WO2021114966A1 (en) 2019-12-09 2020-11-04 Display system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911247601.1A CN113031257B (en) 2019-12-09 2019-12-09 Display system

Publications (2)

Publication Number Publication Date
CN113031257A CN113031257A (en) 2021-06-25
CN113031257B true CN113031257B (en) 2023-08-15

Family

ID=76329562

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911247601.1A Active CN113031257B (en) 2019-12-09 2019-12-09 Display system

Country Status (2)

Country Link
CN (1) CN113031257B (en)
WO (1) WO2021114966A1 (en)

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001077737A1 (en) * 2000-04-05 2001-10-18 Matsushita Electric Industrial Co., Ltd. Color image display apparatus
JP2003015217A (en) * 2001-07-02 2003-01-15 Matsushita Electric Ind Co Ltd Projection type image display device
CN100412608C (en) * 2004-10-15 2008-08-20 杨东佐 Projection system for displaying video image, and optical working method
JP2007178727A (en) * 2005-12-28 2007-07-12 Seiko Epson Corp Illuminator and projector
US7835054B2 (en) * 2007-07-02 2010-11-16 Texas Instruments Incorporated Optical architecture having a rotating polygon for use in imaging systems
TWI383238B (en) * 2007-08-29 2013-01-21 Young Optics Inc Illumination system
US8157388B2 (en) * 2008-03-31 2012-04-17 Texas Instruments Incorporated System and method for a projection display system using an optical lightguide
US20120188519A1 (en) * 2009-08-31 2012-07-26 3M Innovative Properties Company Projection and display system
US8531751B2 (en) * 2011-08-19 2013-09-10 Orbotech Ltd. System and method for direct imaging
US9998717B2 (en) * 2014-12-24 2018-06-12 Prysm, Inc. Scanning beam display system
US10422881B1 (en) * 2018-12-07 2019-09-24 Didi Research America, Llc Mirror assembly for light steering

Also Published As

Publication number Publication date
WO2021114966A1 (en) 2021-06-17
CN113031257A (en) 2021-06-25

Similar Documents

Publication Publication Date Title
US7677736B2 (en) Illumination light source and two-dimensional image display using same
US8004766B2 (en) Illuminating device, illuminating method, image signal processing device, image signal processing method, and image projecting apparatus
US20160327783A1 (en) Projection display system and method
US20230098832A1 (en) Laser projection device and projection display method thereof
US7184104B2 (en) Projector having scanning optics
US20240310707A1 (en) Laser projection apparatus
US20240264515A1 (en) Laser projection apparatus
JP2004264776A (en) Projector and optical device
CN113031257B (en) Display system
CN105980927A (en) Acousto-optic beam steering modulator for a projection system
EP3848753B1 (en) Light source system and control method thereof, display device and control method thereof
WO2020220701A1 (en) Light source system and display device
US11399162B2 (en) Display system
EP3480656B1 (en) Display system and method
US20220171270A1 (en) Method and system for spatial and angular uniformization of light beams
US20230028602A1 (en) Laser source assembly and laser projection apparatus
US20230229011A1 (en) Efficient user-defined sdr-to-hdr conversion with model templates
US20230324779A1 (en) Projection display device
TWI806993B (en) Light path adjustment mechanism and fabrication method thereof
JP2023143587A (en) Projection type display device
JP2004233524A (en) Projector
CN116381929A (en) Scanning type light source and projection display device
JP2024018134A (en) Projection type display device
KR100251112B1 (en) Optical system of ama and projection method by using the same
CN113934009A (en) Projection display system

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant