WO2023245384A1 - 显示模组和投影仪 - Google Patents

显示模组和投影仪 Download PDF

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Publication number
WO2023245384A1
WO2023245384A1 PCT/CN2022/099958 CN2022099958W WO2023245384A1 WO 2023245384 A1 WO2023245384 A1 WO 2023245384A1 CN 2022099958 W CN2022099958 W CN 2022099958W WO 2023245384 A1 WO2023245384 A1 WO 2023245384A1
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Prior art keywords
light
area
lens
incident surface
emitting
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PCT/CN2022/099958
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English (en)
French (fr)
Inventor
王宇杰
王光泉
张伟
蔡斯特
李熙
王金刚
刘小龙
韩天洋
Original Assignee
京东方科技集团股份有限公司
北京京东方显示技术有限公司
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Application filed by 京东方科技集团股份有限公司, 北京京东方显示技术有限公司 filed Critical 京东方科技集团股份有限公司
Priority to PCT/CN2022/099958 priority Critical patent/WO2023245384A1/zh
Priority to CN202280001821.XA priority patent/CN117769674A/zh
Publication of WO2023245384A1 publication Critical patent/WO2023245384A1/zh

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  • the present application relates to the technical fields of optics and projection display, and in particular, to a display module and a projector.
  • the main means of realizing projection display is to make the light emitted by the light source illuminate and pass through the display area of the display panel, so as to project the patterns and colors displayed on the display area onto the receiving surface (such as a screen).
  • optical elements such as lenses may be disposed in the light path from the light source to the display panel in order to guide the light emitted by the light source to facilitate display.
  • these optical elements generally have defects that prevent their performance (such as optical efficiency, illumination, etc.) from meeting people's requirements.
  • a display module including a light source, a first lens, a second lens, and a display panel, wherein the light source includes a light emitting area, the display panel includes a display area, and the light source configured to emit a first light beam through the light emitting area to the first lens, the first lens configured to receive the first light beam, refract the first light beam into a second light beam, and direct the first light beam to the second light beam.
  • a lens emits the second light beam the second lens is configured to receive the second light beam, refract the second light beam into a third light beam, and emit the third light beam to the display panel;
  • the light incident surface of the display panel includes a first irradiation area on a plane, the first irradiation area includes a continuously distributed first effective irradiation area, and the first effective irradiation area includes a position with the strongest illumination;
  • the illumination intensity on the outer contour of the effective illumination area is 1% of the illumination intensity at the strongest illumination position; wherein, I ⁇ 45; wherein, the first lens and the second lens are configured such that the third lens
  • An effective illumination area covers the display area, and on the plane where the light incident surface of the display panel is located, any straight line passing through the center point of the display area is intercepted by the outer contour of the first effective illumination area. is a first line segment and is intercepted by the outer contour of the display area as a second line segment, wherein the ratio of the lengths of the first
  • the difference between the length of the first line segment and the length of the second line segment is in the range of 0-30 mm.
  • the second lens includes a second light incident surface and a second light exit surface
  • the second light beam includes a second illumination area on the plane where the second light incident surface is located
  • the second The irradiation area includes a second effective irradiation area
  • the second effective irradiation area is mapped by the second lens to the first effective irradiation area on the plane where the display panel is located, wherein the second lens is configured to,
  • the area of the second effective illumination area is 90% to 110% of the area of the display area.
  • the outer contour of the light-emitting area has the same shape as the outer contour of the display area.
  • the outer contour of the first effective illumination area is a trapezoid
  • the outer contour of the display area is a rectangle
  • the long side and the short side of the trapezoid are respectively aligned with two sides of the outer contour of the display area.
  • the sides are parallel; the waist of the trapezoid has an included angle with the other two sides of the outer contour of the display area.
  • the first lens includes a first light incident surface and a first light exit surface, the first light incident surface is configured to receive the first light beam, and the first light exit surface is configured to project toward the
  • the second lens emits the second light beam
  • the second lens includes a second light incident surface and a second light exit surface
  • the outer contour of the light emitting area is a rectangle; where the center point of the light emitting area is used as the origin, A straight line along a diagonal of the light-emitting area is used as the x-axis, and the center normal line of the light-emitting area is used as the y-axis to define a first coordinate system, wherein in the first coordinate system, the light source moves toward The first ray emitted by the first lens is refracted by the first light incident surface into a second ray, and the second ray is refracted by the first light exit surface into a third ray, wherein the first light exit surface
  • the section line of the effective light extraction area on the first coordinate system is the first section line, and
  • h is the distance between the second light incident surface and the luminescent area
  • G is the distance between the luminescent area and the first light incident surface
  • S ix1 is the distance between the first ray and the The distance from the intersection of the first light incident surface to the center normal of the light emitting area
  • T ix1 is the distance from the intersection of the third ray and the second light incident surface to the center normal of the light emitting area
  • ⁇ i1 is the angle between the third ray and the center normal line of the light-emitting area
  • ⁇ i1 is the angle between the second ray and the center normal line of the light-emitting area
  • M and N are Constant, where 0 ⁇ M ⁇ 4, 0 ⁇ N ⁇ 4.
  • the first lens includes a first light incident surface and a first light exit surface, the first light incident surface is configured to receive the first light beam, and the first light exit surface is configured to project toward the
  • the second lens emits the second light beam
  • the second lens includes a second light incident surface and a second light exit surface
  • the outer contour of the light emitting area is a rectangle; where the center point of the light emitting area is used as the origin, The extension direction of the long side of the light-emitting area is used as the direction of the x-axis, and the center normal of the light-emitting area is used as the y-axis to define a second coordinate system, wherein in the second coordinate system, the direction of the light source is The first ray emitted by the first lens is refracted by the first light incident surface into a second ray, and the second ray is refracted by the first light exit surface into a third ray, wherein the first light exit surface
  • the section line of the effective light extraction area on the second coordinate system is the second
  • h is the distance between the second light incident surface and the luminescent area
  • G is the distance between the luminescent area and the first light incident surface
  • S ix2 is the distance between the first ray and the The distance from the intersection of the first light incident surface to the center normal of the light emitting area
  • T ix2 is the distance from the intersection of the third ray and the second light incident surface to the center normal of the light emitting area
  • ⁇ i2 is the angle between the third ray and the center normal line of the light-emitting area
  • ⁇ i2 is the angle between the second ray and the center normal line of the light-emitting area
  • P and Q are Constant, where 0 ⁇ P ⁇ 3, 0 ⁇ Q ⁇ 3.
  • the first lens includes a first light incident surface and a first light exit surface, the first light incident surface is configured to receive the first light beam, and the first light exit surface is configured to project toward the The second lens emits the second light beam, wherein the second lens includes a second light incident surface and a second light exit surface, and the outer contour of the light emitting area is a rectangle; wherein, the center point of the light emitting area is taken as The origin is the extension direction of the short side of the light-emitting area as the direction of the x-axis, and the center normal of the light-emitting area is used as the y-axis to define a third coordinate system, wherein in the third coordinate system, the The first ray emitted by the light source toward the first lens is refracted by the first light incident surface into a second ray, and the second ray is refracted by the first light exit surface into a third ray, wherein the first The section line of the effective light-emitting area of the light-emitting surface on
  • h is the distance between the second light incident surface and the luminescent area
  • G is the distance between the luminescent area and the first light incident surface
  • S ix3 is the distance between the first ray and the The distance from the intersection point of the first light incident surface to the center normal line of the light emitting area
  • T ix3 is the distance from the intersection point of the third ray and the second light incident surface to the center normal line of the light emitting area
  • ⁇ i3 is the angle between the third ray and the center normal line of the light-emitting area
  • ⁇ i3 is the angle between the second ray and the center normal line of the light-emitting area
  • C and V are Constant, where 0 ⁇ C ⁇ 2, 0 ⁇ V ⁇ 2.
  • the first light-incident surface is a plane, and the first light-emitting surface is a curved surface.
  • the outer contour of the display area and the outer contour of the light-emitting area are both rectangular, and the second lens includes a second light-incident surface and a second light-emitting surface, and the second light-incident surface and The distance h between the light-emitting areas satisfies the following formula:
  • A is the length of the diagonal line of the display area
  • B is the length of the diagonal line of the light-emitting area
  • G is the distance between the light-emitting area and the first lens
  • L is the display area.
  • ⁇ is the effective divergence half angle of the first beam
  • ⁇ is the effective divergence of the second beam Half angle
  • ⁇ is the effective divergence half angle of the third beam
  • K is a constant
  • the range of K is -5mm ⁇ K ⁇ 5mm.
  • the second lens includes a second light incident surface and a second light exit surface, and the distance h between the second light incident surface and the light emitting area is in the range of 50 mm ⁇ h ⁇ 150 mm.
  • the diagonal length A of the display area ranges from 10 mm ⁇ A ⁇ 200 mm.
  • the diagonal length B of the light-emitting area ranges from 2 mm ⁇ B ⁇ 20 mm.
  • the distance G between the light-emitting area and the first lens ranges from 1 mm ⁇ G ⁇ 3.5 mm.
  • the second lens includes a second light incident surface and a second light exit surface, and the distance L between the center point of the light incident surface of the display area and the center point of the second light incident surface is L The range is 6mm ⁇ L ⁇ 16mm.
  • the focal length F of the second lens satisfies the following formula:
  • A is the diagonal length of the display area
  • h is the distance between the second light incident surface and the light-emitting area
  • G is the distance between the light-emitting area and the first lens
  • E is a constant
  • ⁇ is the effective divergence half angle of the second beam
  • ⁇ is the effective divergence half angle of the third beam, where -2.5mm ⁇ E ⁇ 2.5mm.
  • the focal length F of the second lens ranges from 50 mm ⁇ F ⁇ 200 mm.
  • the range of the effective divergence half angle ⁇ of the first light beam is 40° ⁇ 65°.
  • the range of the effective divergence half angle ⁇ of the third beam is 0° ⁇ 10°
  • the effective divergence half angle ⁇ of the second light beam ranges from 25° ⁇ 45°.
  • the effective divergence half angle ⁇ of the first beam, the effective divergence half angle ⁇ of the second beam, and the effective divergence half angle ⁇ of the third beam satisfy the following formula:
  • the second lens is a Fresnel lens, and the thickness of the second lens along the optical axis direction ranges from 1.5 mm to 2 mm.
  • the display panel is a liquid crystal display panel.
  • the display module further includes a first reflector, wherein the first reflector is located optically downstream of the first lens and optically upstream of the second lens, and the first reflector A mirror is configured to reflect the second light beam from the first lens to the second lens.
  • a projector including the display module according to any embodiment of the present application, a third lens, and a projection lens, wherein the third lens is located on the display Optically downstream of the module, the projection lens is located optically downstream of the third lens.
  • the projector further includes a second reflector, wherein the second reflector is configured to reflect the light emitted by the third lens to the projection lens.
  • Figure 1 schematically shows a cross-sectional view of a display module according to an embodiment of the present application
  • Figure 2 schematically shows the lighting effect diagram of a display module according to an embodiment of the present application
  • Figure 3 schematically shows the lighting effect diagram of a display module according to an embodiment of the present application
  • Figure 4 schematically shows the corresponding relationship between the shape of the light-emitting area of the light source and the shape of the display area;
  • Figure 5 schematically shows a perspective view of the first lens of the display module according to an embodiment of the present application
  • Figure 6 schematically shows one of the special curves used for stitching into the first light-emitting surface
  • Figure 7 schematically shows the optical path diagram of the rays emitted by the light source in the first coordinate system
  • Figure 8 schematically shows the tangent line of the first light exit surface of the first lens
  • Figure 9 schematically shows the second special curve used for stitching into the first light-emitting surface
  • Figure 10 schematically shows the third special curve used for stitching into the first light-emitting surface
  • Figure 11 schematically shows a curved surface fitting diagram of the first light-emitting surface of the first lens of the display module according to an embodiment of the present application
  • Figure 12 schematically shows the structural diagram of the first lens after stitching
  • Figure 13 schematically shows an optical path diagram of a display module according to an embodiment of the present application
  • Figure 14 schematically shows a calculation principle diagram of the focal length of the second lens
  • Figure 15 schematically shows the illumination distribution of the first irradiation area formed on the display panel by the display module according to the embodiment of the present application
  • Figure 16 schematically shows the illumination distribution of a light source according to an embodiment of the present application
  • Figure 17 schematically shows the luminous angle of the light source
  • Figure 18 schematically shows a cross-sectional view of a display module according to an embodiment of the present application.
  • Figures 19A and 19B schematically show software simulation diagrams of the luminous effect of the display module according to embodiments of the present application.
  • Figure 20 schematically shows an illumination test chart of a display module according to an embodiment of the present application
  • Figure 21 schematically shows a cross-sectional view of a projector according to an embodiment of the present application.
  • the illumination distribution of the light beam striking the display panel is uniform and has a high degree of collimation.
  • a single lens cannot adjust the beam to a state of uniform illumination distribution and collimation.
  • Secondary optical processing is required to achieve the ideal illumination distribution and collimation requirements. For example, different optical processing effects are achieved through each of the two lenses, so as to map the light emitted by the light-emitting area with the first size onto the display panel with the second size.
  • one lens also called the first lens
  • plays a converging role used to converge the light emitted by the light source with an effective divergence half angle ⁇ into a light ray with an effective divergence half angle ⁇ , so that it can illuminate the display panel.
  • the light falls on the display area as much as possible, which is beneficial to obtain higher optical efficiency.
  • the other lens also called the second lens
  • the requirements for the effective divergence half angle ⁇ of the collimated beam are different, but in general, the range of ⁇ is generally relatively small.
  • the respective morphology of the two lenses (such as the curved shape of the lens surface) is crucial to the above-mentioned converging and collimating effects.
  • one method of designing lenses is the trial and error method. The trial and error method first establishes the initial structure of the lens based on the known luminous characteristics of the light source, and then uses optical software simulation to obtain the preliminary optical effect of the initial structure. Then the lens surface shape is continuously optimized through optimization algorithms and modules to obtain the best results.
  • the light source is usually regarded as a point light source during calculation, and the shape of the lens is used to map the point light source into a light spot on the display panel.
  • the light source of the projector generally uses a Chip On Board (COB) surface light source, which has a large light-emitting surface. It is a difficult process to collimate it into a light spot the size of the display area of the display panel.
  • COB Chip On Board
  • the partial differential equation method has a large loss of luminous flux of the light source.
  • the multi-surface design method establishes the optical path relationship between two sets of incident wave fronts and outgoing wave fronts based on the luminous characteristics and specific lighting distribution of the light source. By solving the optical path relationship, the discrete surface data of the free-form surface can be obtained.
  • the meshing method is a method derived from the partial differential equation method. The difference is that the meshing method divides the light source and the target surface into n equal parts, and then calculates the initial structure through the partial differential equation method. Then, iterate through the calculation software to obtain the scatter point data and vectors of the free-form surface.
  • This method requires more complex calculations and iterations, and is more difficult. It also optimizes a certain point of the light source to a certain point of the target without considering the influence of other lights, resulting in large deviations in the results.
  • the above method of designing lenses is mainly aimed at point light sources rather than surface light sources, and calculates the value of the local surface shape through partial differential equations.
  • These methods have great limitations, are computationally complex, and cannot even be solved.
  • the resulting lens morphology cannot achieve the desired optical effect.
  • a display module is provided.
  • Figure 1 schematically shows a cross-sectional view of a display module according to an embodiment of the present application.
  • FIG. 2 schematically shows an illumination effect diagram of a display panel of a display module according to an embodiment of the present application.
  • the display module 100 includes a light source 105 , a first lens 110 , a second lens 120 , and a display panel 130 .
  • the light source 105 includes a light emitting area 106
  • the display panel 130 includes a display area 131 .
  • the light-emitting area 106 is a portion of the surface of the light source 105 from which light emerges.
  • light source 105 includes an LED light source.
  • the surface shape of the light source 105 may be a plane or a curved surface, such as a rotationally symmetrical curved surface or an axially symmetrical curved surface.
  • the light source 105 is configured to emit a first light beam 210 to the first lens 110 through the light emitting area 106 .
  • the first lens 110 is configured to receive the first light beam 210 , refract the first light beam 210 into a second light beam 220 , and emit the second light beam 220 toward the second lens 120 .
  • the second lens 120 is configured to receive the second light beam 220 , refract the second light beam 220 into a third light beam 230 , and emit the third light beam 230 toward the display panel 130 .
  • the third light beam 230 At least part of the light received by the light incident surface 135 of the display panel 130 is contributed by the third light beam 230 . In some embodiments, most or all of the light received by the light incident surface 135 of the display panel 130 is contributed by the third light beam 230 .
  • the light incident surface 135 of the display panel 130 includes a first irradiation area 221 on the plane.
  • the first irradiation area 221 is the area where the light emitted by the light source 105 is irradiated on the light incident surface of the display panel 130 (see FIG. 2 ).
  • the first illumination area 221 is located within the outer boundary of the display panel, as shown in FIG. 2 .
  • the first irradiation area 221 may also be located outside the outer boundary of the display panel, that is, the first irradiation area is located on the plane where the display panel is located.
  • the first irradiation area 221 includes a continuously distributed first effective irradiation area 231 .
  • the first effective irradiation area 231 includes the location with the strongest illumination, such as the central area of the first effective irradiation area.
  • the illumination intensity on the outer contour of the first effective illumination area 231 is 1% of the illumination intensity at the strongest illumination position. That is, the first effective irradiation area 231 is a portion of the first irradiation area 221 whose illumination intensity meets specific requirements. In some embodiments, I ranges from I ⁇ 45. Generally speaking, the light intensity of the illuminated area weakens from the strongest light position (such as the center position) to the surroundings. Therefore, the outer contour of the first effective irradiation area 231 is generally the position where the light intensity of the first effective irradiation area 231 is the weakest.
  • the illumination at the position with the weakest illumination intensity in the first effective illumination area 231 can reach 45% of the strongest illumination.
  • the overall illumination of the first effective illumination area 231 is relatively high, and the brightness difference between the center and the outer contour is small. This is advantageous for display modules used in application scenarios such as projectors, for example, to ensure the brightness uniformity of the images projected by the projector.
  • the illumination at the position with the weakest light intensity can reach 70% of the strongest illumination, the brightness uniformity of the display screen is already at a high level. From the perspective of cost saving, the general design I is less than or equal to 70.
  • the first lens 110 and the second lens 120 are configured such that the first effective illumination area 231 covers the display area 131, and on the plane where the light incident surface 135 of the display panel 130 is located, Any straight line passing through the center point 132 of the display area (straight line 260 in FIG. 2 ) is intercepted by the outer contour of the first effective illumination area 231 as a first line segment 261 and is separated by the display area 131
  • the outer contour of is cut into a second line segment 262, wherein the ratio of the lengths of the first line segment 261 and the second line segment 262 is in the range of 1-1.3.
  • the effective portion of the light emitted by the light source 105 in the first illumination area 221 formed on the display panel 130 covers the display area 131.
  • the ratio of the lengths of the first line segment 261 and the second line segment 262 is in the range of 1-1.3, the shape and size of the outline of the first effective illumination area 231 and the outer outline of the display area 131 are very similar. close. This means that the display module will have higher brightness and higher optical efficiency.
  • the ratio between the lengths of the first line segment 261 and the second line segment 262 is less than 1, the display area cannot be completely and effectively illuminated, resulting in the brightness uniformity in the display area not reaching expectations.
  • the ratio of the lengths of the first line segment 261 and the second line segment 262 is greater than 1.3, more of the light emitted by the light source will be located outside the display area, and the light emitted by the light source will not be effectively utilized.
  • the ratio of the first line segment 261 to the second line segment 262 may be between 1.1 and 1.3, such as 1.1, 1.13, 1.15, 1.17, 1.19, 1.2, 1.22, 1.24, 1.26, 1.28, 1.29, 1.3, the first The ratio between the line segment 261 and the second line segment 262 is within this range so that a certain distance can be left between the outer contour of the first effective illumination area 231 and the display area 131, thereby ensuring sufficient utilization efficiency of the light emitted by the light source. design margin.
  • the normal line of the display area 131 and the optical axis of the second lens 120 are parallel.
  • there may be a certain angle between the normal line of the display area 131 and the optical axis of the second lens 120 for example, it may be in a range of greater than 0° and less than or equal to 10°, and the first line segment 261 and The ratio of the second line segment 262 is between 1.1 and 1.3, which can ensure that when there is a certain angle between the normal line of the display area 131 and the optical axis of the second lens 120, the outer contour of the first effective illumination area 231 is The display area 131 is still surrounded, ensuring the display effect.
  • the angle between the normal line of the display area 131 and the optical axis of the second lens 120 may be, for example, 5°.
  • the difference between the length of the first line segment 261 and the length of the second line segment 262 is in the range of 0-30 mm.
  • the length difference is within this range, it can be considered that the shape and size of the outline of the first effective illumination area 231 and the outer outline of the display area 131 are relatively close, and the light emitted by the light source is effectively utilized.
  • the first line segment 261 may be 15mm-30mm longer than the second line segment 262.
  • the first line segment 261 may be 15mm, 16mm, 19mm, 20mm, 22mm, 25mm, 27mm, 29mm longer than the second line segment 262. ,30mm.
  • the length difference between the first line segment 261 and the second line segment 262 within this range can leave a certain distance between the outer contour of the first effective illumination area 231 and the display area 131, while ensuring the utilization efficiency of the light emitted by the light source. Provide sufficient design margin.
  • the normal line of the display area 131 and the optical axis of the second lens 120 are parallel.
  • there may be a certain angle between the normal line of the display area 131 and the optical axis of the second lens 120 for example, it may be in a range of greater than 0° and less than or equal to 10°, and the first line segment 261 and The ratio of the second line segment 262 is between 1.1 and 1.3, which can ensure that when there is a certain angle between the normal line of the display area 131 and the optical axis of the second lens 120, the outer contour of the first effective illumination area 231 is The display area 131 is still surrounded, ensuring the display effect.
  • the angle between the normal line of the display area 131 and the optical axis of the second lens 120 may be, for example, 5°.
  • FIG. 3 schematically shows the lighting effect of the second lens of the display module according to an embodiment of the present application.
  • the second lens 120 includes a second light incident surface 610 and a second light exit surface 620 .
  • the second light beam 220 irradiates the second light incident surface 610 of the second lens 120 , enters the second lens 120 from the second light incident surface 610 , and then leaves the second lens 120 through the second light exit surface 620 of the second lens 120 120.
  • the second lens 120 may be a Fresnel lens, one surface of which is a plane, and the other surface is engraved with a plurality of concentric circles, wherein the plane may serve as the second light incident surface 610 of the second lens 120, The surface engraved with multiple concentric circles can serve as the second light-emitting surface 620 of the second lens 120 .
  • the plane on which the second light incident surface 610 is located includes a second irradiation area 222 .
  • the second irradiation area 222 includes a second effective irradiation area 232 .
  • the second effective illumination area 232 is mapped by the second lens to the first effective illumination area 231 on the plane where the display panel is located. That is, the second effective illumination area 232 can be determined by optically tracing the light irradiating the first effective display area 231 .
  • the second lens 220 is configured such that the area of the second effective illumination area 232 is 90%-110% of the area of the display area 131 . As shown in FIG. 3 , the area of the second effective illumination area 232 is close to the area of the display area 131 .
  • the resulting area of the first effective illumination area 231 will also be the same as the display area.
  • the area of the display module 131 is close to that of the display module 100.
  • the display module 100 has high optical efficiency, and the light incident on the display area 131 also has good collimation. When the display module is used in a projector, it can meet the optical design requirements.
  • the outer contour of the second effective illumination area 232 is located within the contour of the second light incident surface 610 of the second lens 120; the light in the second effective illumination area 232 is refracted by the second lens 120. , falls on the plane where the display panel is located, and these lights form the first effective illumination area.
  • the selection can be made with reference to the size of the display area 131 , for example, so that the size of the second lens 120 is consistent with the size of the display area 131
  • the dimensions are close or even identical.
  • the size of the second lens 120 is close to the size of the display area 131.
  • the second lens 120 can be designed to enlarge or reduce the display area 131 in equal proportions, and the area of the second lens 120 is 90% of the area of the display area 131. -120% range, for example, the area of the second lens 120 is 90%, 95%, 100%, 105%, or 110% of the area of the display area 131.
  • the second light incident surface 610 is contributed by the second light beam 220 . In some embodiments, most or all of the light received by the second light incident surface 610 is contributed by the second light beam 220 .
  • the optical expansion amount U is the integral of the beam area and beam angle when the beam passes through the optical system.
  • dA is the area element
  • ⁇ is the light emitted in the angle direction between the area element and the light source
  • n is the refractive index
  • U is the optical expansion
  • ⁇ is the beam solid angle.
  • the outer contours of the first effective illumination area 231 and the outer contours of the display area 131 are close in shape and size.
  • the area of the second effective illumination area 232 be equal to that of the display area 131
  • the areas are close, so that the area of the first effective irradiation area 231 will also be close to the area of the second effective irradiation area 232, indicating that the second lens 120 has good collimation performance.
  • the number of outer contour edges of the first effective illumination area 231 is the same as the number of outer contour edges of the display area 131 .
  • both the first effective illumination area 231 and the display area 131 are rectangular.
  • the optical axis of the second lens is parallel to the normal line of the display panel, and each side of the outer contour of the first effective illumination area 231 is parallel to the corresponding side of the display area 131 .
  • the outer contour of the first effective illumination area 231 envelops the display area 131 .
  • the outer contour of the first effective illumination area 231 may be a trapezoid due to oblique illumination.
  • the outer contour of the display area 131 is a rectangle; the long and short sides of the trapezoid are parallel to the two sides of the display area 131 respectively; the waist of the trapezoid has an included angle with the other two sides of the outer contour of the display area; for example, two clips The measures of angles are equal.
  • the shape of the lens and the light source can be selected for the shape of the display area 131 .
  • the outer contour of the light-emitting area 106 has the same shape as the outer contour of the display area 131 .
  • FIG. 4 schematically shows the corresponding relationship between the shape of the outer contour of the light-emitting area and the shape of the outer contour of the display area.
  • the shape of the outer contour of the display area 131 is a rectangle
  • the light source should be selected so that the light-emitting area 106 of the light source 105 also has a rectangular shape.
  • the shape of the outer contour of the display area 131 is another polygon, the light source should also have a corresponding shape.
  • the number of sides of the outer contour of the light-emitting area 106 is the same as the number of sides of the display area 131 , and each side of the outer contour of the light-emitting area 106 is on the display panel 130
  • the orthographic projections of are respectively parallel to the corresponding sides of the display area 131 .
  • the orthographic projection 1061 of the light-emitting area 106 on the display panel is also a rectangle, and each side of the rectangular orthographic projection is aligned with the orthogonal projection of the display area 131 .
  • the corresponding sides are parallel.
  • the long side of the orthographic projection 1061 is parallel to the long side of the display area 131
  • the short side of the orthographic projection 1061 is parallel to the short side of the display area 131
  • the size ratio of the outer contour of the light-emitting area 106 is the same as the size ratio of the outer contour of the display area; for example, the outer contour of the light-emitting area 106 is a rectangle with an aspect ratio of 3:2, and the display area The outer contour is also a rectangle with an aspect ratio of 3:2.
  • first lens 110 may be a plano-convex lens.
  • FIG. 5 schematically shows a perspective view of the first lens of the display module according to an embodiment of the present application.
  • the first lens includes a first light incident surface 510 and a first light exit surface 520 .
  • the first light incident surface 510 is configured to receive the first light beam.
  • the first light-emitting surface 520 is configured to emit the second light beam to the second lens 120 .
  • the first light incident surface 510 is a flat surface
  • the first light exit surface 520 is a curved surface.
  • the first light incident surface 510 and the first light exit surface 520 are stitched together to form the first lens 110.
  • the first light-emitting surface 520 can be constructed by stitching some special curve envelopes into a curved surface. Therefore, the curved shape of the first light-emitting surface 520 can be described by the shape of some special curves thereon. Figure 5 is also an envelope diagram of these curves. These curves are described separately below.
  • Figure 6 schematically shows one of the special curves used for stitching into the first light exit surface.
  • the center point of the light-emitting area 106 is used as the origin, the straight line where a diagonal line of the light-emitting area 106 is located is used as the x-axis, and the central normal line of the light-emitting area is used as the y-axis to define the first coordinate system (X 1 OY 1 ). It should be noted that the center point of the light-emitting area 106 should be understood as the geometric center of the planar area circled by the outer contour of the light-emitting area.
  • the surface shape of the light-emitting area 106 is a curved surface (for example, the inside of the light-emitting area 106 protrudes toward the first lens 110 or away from the first lens 110).
  • the center point of the light-emitting area 106 is the light-emitting area.
  • the geometric center of the plane area circled by the outer contour, that is, the geometric center is not on the surface of the light-emitting area 106.
  • the outer contour of the light-emitting area 106 is rectangular. It should be noted that the rectangle may include a rounded rectangle, that is, at least one of the four corners of the rectangle is rounded.
  • Figure 7 schematically shows the optical path diagram of the rays emitted by the light source in the first coordinate system.
  • the light source in Figure 7 is a planar light source.
  • the first ray 710 emitted by the light source 105 to the first lens 110 is refracted by the first light incident surface 510 into a first ray 710 .
  • the second ray 720 is refracted by the first light-emitting surface 520 into a third ray 730 .
  • the light source luminous area 106 and the first light incident surface 510 of the first lens 110 are divided into n parts.
  • Each light-emitting area 106 has a one-to-one correspondence with the first light incident surface 510 to ensure complete mapping of light.
  • the effective light-emitting area of the first light-emitting surface 520 is cut into a first section line 521 by the first coordinate system.
  • the light intensity of the emitted light at a large angle is often smaller than the light intensity of the emitted light at a small angle, so the emitted light with an excessively large angle cannot be effectively utilized.
  • the effective divergence half angle ⁇ of the first light beam corresponds to J% of the maximum intensity If the light emitted by the light-emitting area 106 is within the effective divergence half angle ⁇ after entering the first lens 110 , the area defined by the position reflected on the first light-emitting surface 520 is the effective light-emitting area of the first light-emitting surface 520 .
  • the effective light emitting area of the first light emitting surface 520 can be obtained by optically tracing the light emitted by the light emitting area 106 that is greater than or equal to J% of the maximum light emitting intensity.
  • J 50.
  • the value of J is equal or approximately equal to the value of I.
  • the effective light emitting area of the first light emitting surface 520 can also be defined by the effective divergence half angle ⁇ , that is, it can be considered that among the light emitted by the light emitting area 106, only the light whose divergence half angle is less than or equal to the effective divergence half angle ⁇ is irradiated.
  • the area on the first light-emitting surface 520 is the effective light-emitting area of the first light-emitting surface 520 . That is, the effective light-emitting area of the first light-emitting surface 520 can be obtained by optically tracing the light within the effective divergence half angle ⁇ .
  • the outwardly diffused light emitted at the effective divergence half angle ⁇ of the first light beam 210 is in the first
  • the lens 110 refracts at the ⁇ angle, refracts at the ⁇ angle at the second lens 120 , and then projects to the plane where the display panel 131 is located.
  • the value range of the ⁇ angle may be: 25° ⁇ 45°; the value range of the ⁇ angle may be: 0° ⁇ 10°.
  • G is the distance between the light-emitting area 106 and the first lens 110
  • h is the distance between the second light-incident surface 510 and the light-emitting area 106.
  • the linearity of the first section line 521 can be determined.
  • h is the distance between the second light incident surface 610 of the second lens 120 and the light emitting area 106 (as shown in FIG. 13 ).
  • G is the distance between the light-emitting area 106 and the first light incident surface 510 .
  • the second lens 120 includes a second light incident surface 610 .
  • the light source emits light from point O (O ix1 , O 0 ) of the light-emitting area 106, irradiates point S (S ix1 , S iy1 ) on the first light incident surface 510 of the first lens 110, and enters the first point S from point S. within lens 110.
  • the light then exits the first lens 110 from point P (P ix1 , P iy1 ) on the first light exit surface 520 and irradiates point T (T ix1 , T iy1 ). Therefore, S ix1 is the distance from the intersection point of the first ray 710 and the first light incident surface 510 to the center normal of the light-emitting area 106 . T ix1 is the distance from the intersection point of the third ray 730 and the second light incident surface 610 to the center normal of the light-emitting area 106 .
  • the first ray 710, the second ray 720, and the third ray 730 respectively form angles ⁇ i1 , ⁇ i1 , and ⁇ i1 with the y axis (that is, the center normal line of the light-emitting area 106 ).
  • ⁇ i1 is the angle between the third ray 730 and the center normal of the light-emitting area 106
  • ⁇ i1 is the angle between the second ray 720 and the center normal of the light-emitting area 106 .
  • angle. M and N are constants, where 0 ⁇ M ⁇ 4 and 0 ⁇ N ⁇ 4. In a more specific embodiment, M is approximately equal to 1 and N is approximately equal to 1. In some embodiments, M and N depend on constants of lens processing tolerance, surface normalization error, and surface fitting error, and M and N can be used to adjust the position of the vertex of the first section line. When M is greater than 4 or when N is greater than 4, it may cause the obtained first section line to be unusable.
  • h is the distance between the geometric center of the plane area circled by the outer contour of the light-emitting area 106 and the second light incident surface 610 of the second lens 120 .
  • G is the distance between the geometric center of the plane area circled by the outer contour of the light-emitting area 106 and the first light incident surface 510 of the first lens 110 .
  • n 1 is the refractive index of the medium outside the first lens 110 (for example, air), and n 2 is the refractive index of the material of the first lens 110 .
  • FIG. 8 schematically shows the tangent line of the first light-emitting surface of the first lens. According to Figure 8, it can be seen that the tangent equation of point P is:
  • the point set on the first section line 521 can be obtained.
  • the parameters of the first section line 521 can be obtained, and finally the equation of the first section line 521 is calculated to be the equation represented by the aforementioned formula (2).
  • the cross-section of the coordinate system of the other diagonal of the first light-emitting surface 520 along the light-emitting area 106 can be obtained through similar derivation or mirror image relationship, and will not be described again here.
  • Figure 9 schematically shows the second special curve used for stitching into the first light-emitting surface.
  • the second coordinate system (X 2 OY2 ).
  • the center point of the light-emitting area 106 should be understood as the geometric center of the planar area circled by the outer contour of the light-emitting area.
  • the outer contour of the light-emitting area 102 is, for example, a rectangle.
  • the rays emitted by the light source will also obtain a light path diagram similar to Figure 7, which will not be described again here.
  • the first ray emitted by the light source toward the first lens 110 is refracted by the first light incident surface 510 into a second ray.
  • the second ray is refracted by the first light-emitting surface 520 into a third ray.
  • the effective light-emitting area of the first light-emitting surface 520 is cut into a second section line 522 by the second coordinate system.
  • the definition of the effective light-emitting area of the first light-emitting surface 520 is the same as when describing one of the special curves.
  • h is the distance between the second light incident surface and the luminescent area
  • G is the distance between the luminescent area and the first light incident surface
  • S ix2 is the distance between the first ray and the The distance from the intersection of the first light incident surface to the center normal of the light emitting area
  • T ix2 is the distance from the intersection of the third ray and the second light incident surface to the center normal of the light emitting area
  • ⁇ i2 is the angle between the third ray and the center normal line of the light-emitting area
  • ⁇ i2 is the angle between the second ray and the center normal line of the light-emitting area
  • P and Q are Constant, where 0 ⁇ P ⁇ 3, 0 ⁇ Q ⁇ 3.
  • P is approximately equal to 1 and Q is approximately equal to 1.
  • P and Q depend on lens processing tolerances, surface normalization errors, and surface fitting errors.
  • P and Q can be used to control the position of the vertex of the second section line. For a rectangular plane light source, the length of its long side is less than the length of its diagonal. Therefore, the error of the second section line is smaller than the error of the first section line, so the values of P and Q are smaller than the values of M and N, for example.
  • P is greater than 3 or when Q is greater than 3 it may cause the obtained second cross-section to be unusable.
  • Figure 10 schematically shows the third special curve used for stitching into the first light-emitting surface.
  • the third coordinate system (X 3 OY 3 ).
  • the outer contour of the light-emitting area 102 is rectangular.
  • the center point of the light-emitting area 106 should be understood as the geometric center of the planar area circled by the outer contour of the light-emitting area.
  • the rays emitted by the light source will also obtain a light path diagram similar to Figure 7, which will not be described again here.
  • the first ray emitted by the light source toward the first lens 110 is refracted by the first light incident surface 510 into a second ray.
  • the second ray is refracted by the first light-emitting surface 520 into a third ray.
  • the effective light-emitting area of the first light-emitting surface 520 is cut into a third section line 523 by the third coordinate system.
  • the definition of the effective light-emitting area of the first light-emitting surface 520 is the same as when describing one of the special curves.
  • h is the distance between the second light incident surface and the luminescent area
  • G is the distance between the luminescent area and the first light incident surface
  • S ix3 is the distance between the first ray and the The distance from the intersection point of the first light incident surface to the center normal line of the light emitting area
  • T ix3 is the distance from the intersection point of the third ray and the second light incident surface to the center normal line of the light emitting area
  • ⁇ i3 is the angle between the third ray and the central normal line of the light-emitting area
  • ⁇ i3 is the angle between the second ray and the central normal line of the light-emitting area
  • C and V constants , where 0 ⁇ C ⁇ 2, 0 ⁇ V ⁇ 2.
  • C is approximately equal to 1 and V is approximately equal to 1.
  • C and V depend on lens processing tolerances, surface normalization errors, and surface fitting errors.
  • the length of its short side is smaller than the length of its long side. Therefore, the error of the third section line is smaller than the error of the second section line, so the values of C and V are generally smaller than the values of P and Q.
  • C is greater than 2 or when V is greater than 2
  • the resulting third cross-section may be unusable.
  • the outer contour of the light-emitting area 106 of the light source is a rectangle with a length of 13 mm and a width of 9 mm.
  • the display area 131 of the display panel has a length of 101 mm and a width of 58 mm.
  • the distance G between the light-emitting area 106 and the first light incident surface 510 is 2 mm.
  • the distance L between the second entrance surface 610 of the second lens and the liquid crystal panel is 8 mm.
  • the point sets of each of the three sections can be obtained using formulas (2), (11), and (12).
  • the curve equation of the first section line 521 can be obtained respectively:
  • the specific value of the highest power depends on the calculation results of the point set and the curve fit. For example, in the aforementioned formulas (13)-(15), when the highest power is taken to the third degree, the fitted curve fits the curve composed of the point set more closely, so the highest power is set to the third degree. Depending on the point set, it is not excluded that the highest power of the curve is other values, such as the 4th power.
  • the curved surface of the first light-emitting surface 520 can be obtained through these four curves.
  • FIG. 11 schematically shows a curved surface fitting diagram of the first light-emitting surface of the first lens of the display module according to an embodiment of the present application.
  • FIG. 12 schematically shows a structural view of the first lens after stitching.
  • the first lens fitted by the above formula has excellent optical performance and can be used to make the shape and area of the outer contour of the first effective illumination area 231 close to the shape and area of the outer contour of the display area 131 , thereby improving the display mode.
  • Optical efficiency of group 110 is excellent optical performance and can be used to make the shape and area of the outer contour of the first effective illumination area 231 close to the shape and area of the outer contour of the display area 131 , thereby improving the display mode.
  • At least part of the light entering the display area 131 is formed by the light emitted from the light-emitting area 106 passing through the first lens 110 and the second lens 120. These light rays can be traced on the first light-emitting surface.
  • 520 delineates a continuously distributed area, which is defined as the effective projection area.
  • the effective projection area is located in the effective light emitting area; the fourth section line cut by the first coordinate system in the effective projection area is located in the first section line 521, and any point on the fourth section line Satisfies equation (2); the fifth section line cut by the second coordinate system in the effective projection area is located within the second section line 522, and any point on the fifth section line satisfies equation (11); effective projection The sixth section line cut by the third coordinate system is located within the third section line 523, and any point on the sixth section line satisfies the equation (12).
  • the curved surface structure of the first lens 110 is related to the distance h between the second light incident surface 610 and the light-emitting area 106.
  • the method of determining distance h will be introduced below.
  • FIG. 13 schematically shows an optical path diagram of a display module according to an embodiment of the present application.
  • the schematic angle is a diagonal direction along the light-emitting area 106 , which is the same viewing angle as in FIG. 7 .
  • the outer contour of the display area 131 and the outer contour of the light-emitting area 106 are both rectangles, A is the diagonal length of the display area 131, B is the diagonal length of the light-emitting area 106, and G is the light-emitting area 106
  • ⁇ is the effective divergence half angle of the first beam 210 .
  • the light emitted at the effective divergence half angle ⁇ of the first light beam 210 on the outline of the light-emitting area 105 is refracted at the ⁇ angle at the first lens 110 and at the ⁇ angle at the second lens 120 .
  • ⁇ is defined as the effective divergence half angle of the second beam 220
  • ⁇ is defined as the effective divergence half angle of the third beam 230 .
  • K is a constant, and the value of K ranges from -5mm to 5mm.
  • the value range of K is in the range of 0-2mm. Further preferably, the value range of K is in the range of 0-1 mm.
  • the effective divergence half angle ⁇ of the second light beam 220 reflects the converging ability of the first lens 110 .
  • the material and surface shape of the first lens 110 can be selected to determine ⁇ .
  • the effective divergence half angle ⁇ of the third beam 230 reflects the converging ability of the second lens 120 .
  • the material and surface shape of the second lens 120 can be selected to determine ⁇ . The stronger the converging ability of the second lens 120 is, the smaller the effective divergence half angle ⁇ of the third light beam 230 is.
  • K can depend on assembly tolerances and machining tolerances. Specifically, the value of K can refer to the assembly of components in the display module and the error between each component. The value range of K is within the range of -5mm to 5mm, which can ensure better imaging quality. By substituting these quantities, the distance h between the second light incident surface 610 and the light emitting area 106 can be obtained. Based on the distance h between the second light incident surface 610 and the light emitting area 106, the installation position of the second lens 120 can be determined.
  • the distance G between the light-emitting area 106 and the first lens 110 is in the range of 1 mm ⁇ G ⁇ 3.5 mm.
  • a distance of at least 1 mm needs to be left between the light source 105 and the first lens 110; and when G becomes larger, the size of the first lens 110 needs to be increased to effectively receive light, which is not conducive to the display model.
  • the range of h satisfies: 50mm ⁇ h ⁇ 150mm.
  • h is greater than 150mm, the display module is too large and has no applicability.
  • h is less than 50mm, the light efficiency may be reduced.
  • the value of the distance L between the center point of the light incident surface of the display area 131 and the center point of the second light incident surface 610 of the second lens 120 can be directly selected within an appropriate range.
  • the value range of distance L can be 6mm-16mm. Within this range, the second lens 120 is easier to assemble and has good heat dissipation performance. When L is less than 6 mm, the air channel between the display area 131 and the second lens 120 is too narrow and cannot fully dissipate heat. When L is greater than 16mm, the wind pressure will decrease, resulting in a decrease in heat dissipation effect.
  • distance L may be 9 mm or 11 mm.
  • the focal length F of the second lens 120 may be determined according to the distance h between the second light incident surface 610 and the light emitting area 106 .
  • Figure 14 schematically shows a calculation principle diagram of the focal length of the second lens. When the light passes through the lens, a parallel line of the incident light is drawn at the center of the lens. The intersection point of the parallel line and the outgoing light is a perpendicular line to the optical axis. The vertical position is the focus F of the lens. It can be obtained from Figure 14 that the focal length F of the second lens 120 satisfies the following formula:
  • A is the diagonal length of the display area
  • h is the distance between the second light incident surface 510 and the light-emitting area 106
  • G is the distance between the light-emitting area 106 and the first lens 110
  • E is a constant, Among them, -2.5 ⁇ E ⁇ 2.5.
  • the constant E takes into account the processing tolerance of the second lens 120 and the rounding tolerance. Since the F value may not be rounded after being calculated, considering the convenience of the design, it is necessary to make F divisible by 5. In this case, E can be used for deployment. For example, the deployment method can be to adjust F to The closest number divisible by 5. When the degree of proximity is the same, take the larger focal length (for example, calculate , adjust to 75mm).
  • the F value may only satisfy that it is an integer. In this embodiment, -0.5 ⁇ E ⁇ 0.5, that is, when calculated Finally, use rounding method to make the F value an integer. In some embodiments, the F value may not be an integer. It should be noted that, if the difference between the actually measured focal length of the second lens 120 and the above calculated value is within +/-5 mm, it falls within the disclosure scope of the present application.
  • the focal length F of the second lens 120 may be in the range of 50mm-200mm, which mainly depends on the size of the applicable display panel.
  • the second lens 120 is understood as an ideal lens, that is, a lens with a thickness of 0.
  • the thickness of the second lens 120 cannot be made to 0.
  • the second lens 120 may be a Fresnel lens. But even so, the Fresnel lens still has a thickness, and the thickness of the Fresnel lens can be in the range of 1.5mm-2mm.
  • One surface of the Fresnel lens is a plane, and the other surface is engraved with a plurality of concentric circles.
  • the plane can be used as the second light incident surface 610 of the second lens 120 , and the surface engraved with a plurality of concentric circles can be used as the second light incident surface 610 of the second lens 120 .
  • the second light-emitting surface 620 of the lens 120 When performing the above calculation, this plane is used as the positioning plane, that is, when determining the distance between the display area and the second lens, the center point of the light incident surface of the display area is The distance between the center points of the two incident light surfaces is used as the measurement object.
  • FIG. 15 schematically shows the illumination distribution of the first irradiation area formed on the display panel 131 by the display module according to the embodiment of the present application.
  • area 136 schematically shows the position of the outer contour of the display area 131 .
  • the illumination at any point on the outer contour 136 of the display area 131 is greater than or equal to 50% of the illumination at the maximum illumination point in the display area 131, and the illumination of the entire display area is greater than 50% of the maximum illumination. Achieved a very good display effect.
  • Figure 16 schematically illustrates an illumination distribution diagram of an exemplary light source that may be used in embodiments of the present application.
  • the illumination of the light beam emitted by the light source (for example, the first light beam 210) is related to the effective divergence half angle ⁇ (that is, the effective divergence angle of the light source is 2 ⁇ ).
  • the effective divergence half angle ⁇ of the first light beam 210 is related to the illuminance of the edge ray of the light source.
  • the display module uses the light source represented in Figure 16, if the edge light illumination is required to reach at least 50% of the maximum illumination, ⁇ can be set to 60°.
  • the effective divergence half angle ⁇ of the second beam 220 should be taken before ⁇ and ⁇ .
  • the value range of ⁇ is in the range of 25°-45° to improve the collimation of the light emitted from the second lens.
  • ⁇ ( ⁇ + ⁇ )/2, which facilitates design and achieves better light extraction effect.
  • the display panel 130 is a liquid crystal display panel.
  • the display area 131 of the liquid crystal display panel is used to display images.
  • the display area 131 of the liquid crystal display panel is, for example, rectangular.
  • Figure 18 schematically shows a cross-sectional view of a display module according to an embodiment of the present application.
  • the display module 100 further includes a first reflector 140.
  • the first reflector 140 is located optically downstream of the first lens 110 and optically upstream of the second lens 120 .
  • the term optical downstream refers to the direction in which light travels. Therefore, the light emitted by the first lens 110 will illuminate the first reflecting mirror 140 .
  • the term optical upstream refers to the direction from which light originates. Therefore, the light reflected by the first reflecting mirror 140 , that is, the light emitted by the first lens 110 is reflected by the first reflecting mirror 140 onto the second lens 120 .
  • the first mirror 140 is configured to direct the second light beam 220 from the first lens 110 to the second lens 120 .
  • the normal of the first mirror 140 may be at an angle of 45° with the optical axis of the second lens 120 .
  • the distance h between the second light incident surface 610 and the light-emitting area 106 can be understood as the normal direction of the light-emitting area 106 passing through the center of the light-emitting area 106
  • the total path length of the emitted light after being reflected by the first reflecting mirror 140 reaches the light incident surface of the second lens 120 .
  • the surface shape of the light-emitting area 106 is a curved surface, the light emitted from the center of the light-emitting area 106 is deemed to be emitted from the geometric center of the plane area circled by the outer contour of the light-emitting area 106 .
  • the structure of the display module can be fine-tuned based on software simulation results.
  • Figures 19A and 19B schematically show software simulation diagrams of the luminous effect of the display module according to embodiments of the present application.
  • the parameters of the light source, the first lens, and the second lens described in the above embodiments are input into the simulation software, and the distance between the light source, the first lens, the second lens, and the display panel is also input into the simulation software.
  • the illumination and luminous flux can be analyzed.
  • the parameters of the lens (such as the surface structure of the lens) can be continuously optimized until the required parameters are reached to determine the final structure of the display module.
  • the light-emitting structure can completely incident the light emitted by the light source onto the display panel, and limit the outer contour shape and area of the effective display area mapped by the light source on the display panel to be close to the display area.
  • the outer contour shape and area improve the optical efficiency and also make the emitted light have the required corner uniformity.
  • this application also provides a method for designing a display module.
  • the display module according to the embodiment of the present application can be designed.
  • This method can be used to design a display module having a light source, a first lens, a second lens, and a display panel, wherein the first lens and the second lens are located between the light source and the display panel, and the first lens is more precise than the second lens. Close to the light source, the second lens is closer to the display panel than the first lens.
  • This method can design the parameters of the first lens and the second lens and the positional relationship between these elements when the dimensions of the light source and the display panel are known, so as to achieve various optical effects described above.
  • the distance between the display panel and the second lens is first determined based on the heat dissipation requirements of the lighting equipment (that is, the ventilation space required by the lighting equipment that is sufficient to support heat dissipation). Then, the distance between the light source and the second lens is determined based on the distance between the display panel and the second lens, the size of the display area of the display panel and the light emitting area of the light source, and the distance between the first lens and the light source. Then, the focal length of the second lens is determined based on the distance between the light source and the second lens and the size of the display panel.
  • the equations of some special curves on the light exit surface of the first lens can be determined according to the previous formulas, and these curves can be used to fit the curved surface to obtain the curved surface shape of the light exit surface of the first lens. Then, a base is provided for the first lens, and simulation software is used for debugging to obtain the physical structure of the first lens.
  • FIG. 21 schematically shows a cross-sectional view of a projector according to an embodiment of the present application.
  • the projector 200 includes the display module 100 according to any embodiment of the present application.
  • the projector 200 further includes a third lens 300 and a projection lens 400 .
  • the third lens 300 is located optically downstream of the display module 100
  • the projection lens 400 is located optically downstream of the third lens 300 .
  • the third lens 300 can perform initial imaging of the image displayed on the display panel 130 to make the image an upright virtual image, and converge the light emitted from the display panel 130 to reduce the lens aperture.
  • the third lens 300 may be a Fresnel lens.
  • the projection lens 400 can enlarge the image and improve the aberration.
  • the projector 200 further includes a second reflecting mirror 500 .
  • the second reflecting mirror 500 is configured to reflect the light emitted by the third lens 300 to the projection lens 400 .
  • the normal line of the second reflecting mirror 500 may form an included angle of 45° with the optical axis of the third lens 300 .
  • Figure 20 schematically shows an illumination test chart of a projector according to an embodiment of the present application.
  • the image projected by the projector is divided into nine parts.
  • the measuring equipment is a Konica Minolta CL-200A color illuminance meter. After testing, the illumination uniformity of the projection screen was 61.2%, and the overall design met the requirements.

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Abstract

本申请公开了一种显示模组和投影仪。该显示模组包括光源、第一透镜、第二透镜、和显示面板，其中，光源包括发光区，显示面板包括显示区，光源通过发光区发射第一光束，第一透镜将第一光束折射成第二光束，第二透镜将第二光束折射成第三光束。显示面板的入光面所在平面上包括第一照射区，第一照射区包括连续分布的第一有效照射区，其内包括光照最强位置；第一有效照射区的外轮廓上的光照强度为光照最强位置的I％，I≥45；第一有效照射区覆盖显示区，并且，在显示面板的入光面所在平面上，穿过显示区的中心点的任一直线被第一有效照射区的外轮廓截取为第一线段、并被显示区的外轮廓截取为第二线段，其中第一线段与第二线段的长度之比在1-1.3范围内。

Description

显示模组和投影仪 技术领域
本申请涉及光学和投影显示的技术领域，尤其涉及一种显示模组和投影仪。
背景技术
在相关技术中，实现投影显示的主要手段是使光源发出的光照射并穿过显示面板的显示区，以将显示区上显示的图案和颜色投射到接收面(例如幕布)上。在一些投影设备中，可以将诸如透镜的光学元件设置在从光源到显示面板的光路中，以便对光源发出的光进行有利于显示的引导。然而，这些光学元件普遍存在缺陷，使其性能(例如，光学效率、照度等)无法满足人们的要求。
发明内容
根据本申请的一方面，提供了一种显示模组，包括光源、第一透镜、第二透镜、和显示面板，其中，所述光源包括发光区，所述显示面板包括显示区，所述光源配置成通过所述发光区向所述第一透镜发射第一光束，所述第一透镜配置成接收所述第一光束、将所述第一光束折射成第二光束、以及向所述第二透镜发射所述第二光束，所述第二透镜配置成接收所述第二光束、将所述第二光束折射成第三光束、以及向所述显示面板发射所述第三光束；其中，所述显示面板的入光面所在平面上包括第一照射区，所述第一照射区包括连续分布的第一有效照射区，所述第一有效照射区内包括光照最强位置；所述第一有效照射区的外轮廓上的光照强度为所述光照最强位置的光照强度的I％；其中，I≥45；其中，所述第一透镜和所述第二透镜配置成，使所述第一有效照射区覆盖所述显示区，并且，在所述显示面板的入光面所在平面上，穿过所述显示区的中心点的任一直线被所述第一有效照射区的外轮廓截取为第一线段、并被所述显示区的外轮廓截取为第二线段，其中所述第一线段与所述第二线段的长度之比在1-1.3范围内。
在一些实施例中，在所述显示面板的入光面所在平面上，所述第一线段的长度与所述第二线段的长度的差在0-30mm范围内。
在一些实施例中，所述第二透镜包括第二入光面和第二出光面，所述第二光束在所述第二入光面所在的平面上包括第二照射区，所述第二照射区包括第二有效照射区，所述第二有效照射区被所述第二透镜在所述显示面板所在平面上映射为所述第一有效照射区，其中，所述第二透镜配置成，使得所述第二有效照射区的面积是所述显示区的面积的90％至110％。
在一些实施例中，所述发光区的外轮廓与所述显示区的外轮廓形状相同。
在一些实施例中，所述第一有效照射区的外轮廓为梯形，所述显示区的外轮廓为矩形；所述梯形的长边与短边分别与所述显示区的外轮廓的两条边平行；所述梯形的腰与所述显示区的外轮廓的另外两条边都具有夹角。
在一些实施例中，所述第一透镜包括第一入光面和第一出光面，所述第一入光面配置成接收所述第一光束，所述第一出光面配置成向所述第二透镜发射所述第二光束，所述第二透镜包括第二入光面和第二出光面，所述发光区的外轮廓为矩形；其中，以所述发光区的中心点作为原点，以所述发光区的一条对角线所在的直线作为x轴，以所述发光区的中心法线作为y轴定义第一坐标系，其中，在所述第一坐标系内，所述光源向所述第一透镜发出的第一射线被所述第一入光面折射为第二射线，所述第二射线被所述第一出光面折射为第三射线，其中，所述第一出光面的有效出光区在所述第一坐标系上的截线是第一截线，所述第一截线上的任意一点(x 1，y 1)满足下述方程：
Figure PCTCN2022099958-appb-000001
其中，h是所述第二入光面与所述发光区之间的距离，G是所述发光区与所述第一入光面之间的距离，S ix1是所述第一射线与所述第一入光面的交点到所述发光区的中心法线的距离，T ix1是所述第三射线与所述第二入光面的交点到所述发光区的中心法线的距离，β i1是所述第三射线与所述发光区的中心法线之间的夹角，θ i1是所述第二射线与所述发光区的中心法线之间的夹角，M和N是常数，其中0≤M≤4，0≤N ≤4。
在一些实施例中，所述第一透镜包括第一入光面和第一出光面，所述第一入光面配置成接收所述第一光束，所述第一出光面配置成向所述第二透镜发射所述第二光束，所述第二透镜包括第二入光面和第二出光面，所述发光区的外轮廓为矩形；其中，以所述发光区的中心点作为原点，以所述发光区的长边的延伸方向作为x轴的方向，以所述发光区的中心法线作为y轴定义第二坐标系，其中，在所述第二坐标系内，所述光源向所述第一透镜发出的第一射线被所述第一入光面折射为第二射线，所述第二射线被所述第一出光面折射为第三射线，其中，所述第一出光面的有效出光区在所述第二坐标系上的截线是第二截线，所述第二截线上的任意一点(x 2，y 2)满足下述方程：
Figure PCTCN2022099958-appb-000002
其中，h是所述第二入光面与所述发光区之间的距离，G是所述发光区与所述第一入光面之间的距离，S ix2是所述第一射线与所述第一入光面的交点到所述发光区的中心法线的距离，T ix2是所述第三射线与所述第二入光面的交点到所述发光区的中心法线的距离，β i2是所述第三射线与所述发光区的中心法线之间的夹角，θ i2是所述第二射线与所述发光区的中心法线之间的夹角，P和Q是常数，其中0≤P≤3，0≤Q≤3。
在一些实施例中，所述第一透镜包括第一入光面和第一出光面，所述第一入光面配置成接收所述第一光束，所述第一出光面配置成向所述第二透镜发射所述第二光束，其中，所述第二透镜包括第二入光面和第二出光面，所述发光区的外轮廓为矩形；其中，以所述发光区的中心点作为原点，以所述发光区的短边的延伸方向作为x轴的方向，以所述发光区的中心法线作为y轴定义第三坐标系，其中，在所述第三坐标系内，所述光源向所述第一透镜发出的第一射线被所述第一入光面折射为第二射线，所述第二射线被所述第一出光面折射为第三射线，其中，所述第一出光面的有效出光区在所述第三坐标系上的截线是第三截线，所述第三截线上的任意一点(x 3，y 3)满足下述方程：
Figure PCTCN2022099958-appb-000003
其中，h是所述第二入光面与所述发光区之间的距离，G是所述发光区与所述第一入光面之间的距离，S ix3是所述第一射线与所述第一入光面的交点到所述发光区的中心法线的距离，T ix3是所述第三射线与所述第二入光面的交点到所述发光区的中心法线的距离，β i3是所述第三射线与所述发光区的中心法线之间的夹角，θ i3是所述第二射线与所述发光区的中心法线之间的夹角，C和V是常数，其中0≤C≤2，0≤V≤2。
在一些实施例中，所述第一入光面是平面，所述第一出光面是曲面。
在一些实施例中，所述显示区的外轮廓和所述发光区的外轮廓都是矩形，所述第二透镜包括第二入光面和第二出光面，所述第二入光面与所述发光区之间的距离h满足下述公式：
Figure PCTCN2022099958-appb-000004
其中，A是所述显示区的对角线的长度，B是所述发光区的对角线的长度，G是所述发光区与所述第一透镜之间的距离，L是所述显示区的入光面的中心点与所述第二透镜的第二入光面的中心点之间的距离，α是所述第一光束的有效发散半角，β是所述第二光束的有效发散半角，γ是所述第三光束的有效发散半角，K是常数，K的范围是-5mm≤K≤5mm。
在一些实施例中，所述第二透镜包括第二入光面和第二出光面，所述第二入光面与所述发光区之间的距离h的范围是50mm≤h≤150mm。
在一些实施例中，所述显示区的对角线的长度A的范围是10mm≤A≤200mm。
在一些实施例中，所述发光区的对角线的长度B的范围是2mm≤B≤20mm。
在一些实施例中，所述发光区与所述第一透镜之间的距离G的范围是1mm≤G≤3.5mm。
在一些实施例中，所述第二透镜包括第二入光面和第二出光面，所述显示区的入光面的中心点与所述第二入光面的中心点之间的距离L的范围是6mm≤L≤16mm。
在一些实施例中，所述第二透镜的焦距F满足下述公式：
Figure PCTCN2022099958-appb-000005
其中，A是所述显示区的对角线长度，h是所述第二入光面与所述发光区之间的距离，G是所述发光区与所述第一透镜之间的距离，E是常数，β是所述第二光束的有效发散半角，γ是所述第三光束的有效发散半角，其中，-2.5mm＜E≤2.5mm。
在一些实施例中，所述第二透镜的焦距F的范围是50mm≤F≤200mm。
在一些实施例中，所述第一光束的有效发散半角α的范围是40°≤α≤65°。
在一些实施例中，所述第三光束的有效发散半角γ的范围是0°≤γ≤10°
在一些实施例中，所述第二光束的有效发散半角β的范围是25°≤β≤45°。
在一些实施例中，所述第一光束的有效发散半角α、所述第二光束的有效发散半角β、所述第三光束的有效发散半角γ满足下述公式：
β＝(α+γ)/2。
在一些实施例中，所述第二透镜是菲涅尔透镜，并且所述第二透镜沿光轴方向的厚度的范围是1.5mm-2mm。
在一些实施例中，所述显示面板是液晶显示面板。
在一些实施例中，所述显示模组还包括第一反射镜，其中所述第一反射镜位于所述第一透镜的光学下游和所述第二透镜的光学上游，并且所述第一反射镜配置成将所述第二光束从所述第一透镜反射到所述第二透镜。
根据本申请的另一方面，还提供了一种投影仪，包括根据本申请任一实施例所述的显示模组、第三透镜、以及投影透镜，其中，所述第三透镜位于所述显示模组的光学下游，所述投影透镜位于所述第三透 镜的光学下游。
在一些实施例中，所述投影仪还包括第二反射镜，其中，所述第二反射镜配置成将所述第三透镜发出的光反射到所述投影透镜。
附图说明
为了更清楚地描述本申请实施例中的技术方案，下面将对实施例中所需要使用的附图作简单地介绍。显而易见地，下面描述中的附图仅仅是本申请的一些实施例。对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。在附图中，相同或相似的元件可以由相同或相似的图案或符号来表示。应理解，除非有明确的描述，否则附图中的图案或符号仅用于对元件进行区分，但并不用于限定元件的形状。在本申请的附图中：
图1示意性地示出了根据本申请实施例的显示模组的截面图；
图2示意性地示出了根据本申请实施例的显示模组的光照效果图；
图3示意性地示出了根据本申请实施例的显示模组的光照效果图；
图4示意性地示出了光源发光区的形状与显示区的形状的对应关系；
图5示意性地示出了根据本申请实施例的显示模组的第一透镜的立体图；
图6示意性地示出了用于缝合成第一出光面的特殊曲线之一；
图7示意性地示出了第一坐标系中光源发出的射线的光路图；
图8示意性地示出了第一透镜的第一出光面的切线；
图9示意性地示出了用于缝合成第一出光面的特殊曲线之二；
图10示意性地示出了用于缝合成第一出光面的特殊曲线之三；
图11示意性地示出了根据本申请实施例的显示模组的第一透镜的第一出光面的曲面拟合图；
图12示意性地示出了经过缝合后的第一透镜的结构图；
图13示意性地示出了根据本申请实施例的显示模组的光路图；
图14示意性地示出了第二透镜的焦距的计算原理图；
图15示意性地示出了根据本申请实施例的显示模组在显示面板上形成的第一照射区的照度分布；
图16示意性地示出了根据本申请实施例的光源照度分布；
图17示意性地示出了光源的发光角度；
图18示意性地示出了根据本申请实施例的显示模组的截面图；
图19A和19B示意性地示出了根据本申请实施例的显示模组的发光效果的软件模拟图；
图20示意性地示出了根据本申请实施例的显示模组的照度测试图；
图21示意性地示出了根据本申请实施例的投影仪的截面图。
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行描述。显然，所描述的实施例仅仅是本申请的一部分实施例，而不是全部的实施例。基于所描述的实施例，本领域普通技术人员在没有做出创造性劳动的前提下所获得的所有其他实施例都属于本申请的保护范围。
在投影显示中，希望照射到显示面板的光束的照度分布均匀，并具有较高的准直度。单个透镜无法将光束调整为照度分布均匀且准直的状态，需要二次光学处理才能达到理想的照度分布和准直度需求。例如，通过两个透镜各自实现不同的光学处理效果，以便将具有第一尺寸的发光区发出的光映射到具有第二尺寸的显示面板上。在这两个透镜中，一个透镜(也称第一透镜)起收束作用，用于将光源发射的有效发散半角为α的光线收束成有效发散半角为β的光线，使得照射到显示面板上的光尽可能落在显示区内，这对于获得较高的光学效率是有利的。另一个透镜(也称第二透镜)起准直作用，用于将经过收束的光束准直成有效发散半角为γ的光线。在不同领域中，对准直光束的有效发散半角γ的要求不相同，但总体来说，γ的范围一般比较小。这两个透镜各自的形貌(例如透镜表面的曲面形状)对于上述收束作用和准直作用是至关重要的。
然而，发明人发现，在相关技术中，这两个透镜并不能带来令人满意的光学效果。一个原因是，在相关技术中，具有不同尺寸显示面板的投影仪可能共用透镜，而没有针对投影仪中各个器件的尺寸和位置进行具体的调整，最终导致光学效率较低。另一原因是，即使想要针对不同的投影仪而单独设计透镜，当前的透镜设计方法存在一些问题。在相关技术中，一种设计透镜的方法是试错法。试错法首先根据已知 的光源发光特性，建立透镜的初始结构，再应用光学软件模拟仿真，获取该初始结构的初步的光学效果。然后通过优化算法和模块不断的优化透镜表面面型，以得出最优的结果。在试错法中，优化结果的好坏往往和迭代次数相关。这样的方式对初始结构的要求比较高，并且需要较大的工作量才能完成。另一种设计透镜的方法是数值法。数值法具体包括偏微分方程法、多曲面设计法和网格划分法。偏微分方程法主要根据光源的入射光线矢量、出射光线矢量和自由曲面法向量的微分关系，结合斯涅尔(Snell)定律，建立偏微分方程组。然后以数值求解的方式获得透镜自由曲面的数值。但此种方法适用于小体积光源，计算时通常将光源视为点光源，并使透镜的形貌用于将点光源在显示面板上映射成光斑。然而，投影仪的光源一般采用板上芯片(Chip On Board，COB)面光源，其发光面较大，将其准直成显示面板的显示区大小的光斑是较为困难的过程。偏微分方程法对光源的光通量损失较大。多曲面设计法根据光源的发光特点和特定照明分布，建立两组入射波前和出射波前之间的光程关系，通过求解该光程关系可以得到自由曲面的离散面型数据。但是这种方法不能解决非对称的照明问题，因为用该方法构建的方程特别复杂，有很高的求解难度。网格划分法是从偏微分方程法中衍生出的一种方法，与之区别在于网格划分法将光源和目标面划分成n等份，再通过偏微分方程法进行计算初始结构。然后，再通过计算软件进行迭代，获取自由曲面的散点数据和向量。该方法需要的计算量和迭代次数较复杂，难度较高，并且是将光源的某点优化至目标的某点，不考虑其他光线的影响，结果偏差较大。总之，上述设计透镜的方法主要针对点光源而非面光源，通过偏微分方程计算局部面型的数值。这些方法的局限性较大，并且运算复杂，甚至无法求解，所得到的透镜的形貌无法实现期望的光学效果。
根据本申请的一方面，提供了一种显示模组。图1示意性地示出了根据本申请实施例的显示模组的截面图。图2示意性地示出了根据本申请实施例的显示模组的显示面板的光照效果图。如图1所示，显示模组100包括光源105、第一透镜110、第二透镜120、和显示面板130。所述光源105包括发光区106，所述显示面板130包括显示区131。发光区106是光源105的表面上出射光的部分。在更具体的实施例中，光源105包括LED光源。光源105的面型可以是平面，也可以是曲面， 例如旋转对称的曲面或者轴对称的曲面。所述光源105配置成通过所述发光区106向所述第一透镜110发射第一光束210。所述第一透镜110配置成接收所述第一光束210、将所述第一光束210折射成第二光束220、以及向所述第二透镜120发射所述第二光束220。所述第二透镜120配置成接收所述第二光束220、将所述第二光束220折射成第三光束230、以及向所述显示面板130发射所述第三光束230。
需要说明的是，显示面板130的入光面135接收的至少部分光由第三光束230贡献。在一些实施例中，显示面板130的入光面135接收的大部分或全部的光由第三光束230贡献。
显示面板130的入光面135所在平面上包括第一照射区221，第一照射区221是光源105发出的光照射在在显示面板130的入光面所在平面上的区域(见图2)。在一些实施例中，所述第一照射区221位于所述显示面板的外边界之内，如图2所示出的。在另一些实施例中，所述第一照射区221还可能位于所述显示面板的外边界之外，也即第一照射区位于显示面板所在平面上。所述第一照射区221包括连续分布的第一有效照射区231。所述第一有效照射区231内包括光照最强位置，例如所述第一有效照射区的中心区域。所述第一有效照射区231的外轮廓上的光照强度为所述光照最强位置的光照强度的I％。也就是，第一有效照射区231是第一照射区221中光照强度满足特定要求的部分。在一些实施例中，I的范围是I≥45。通常来说，照射区的光照强度从光照最强位置(例如中心位置)向四周减弱。因此，第一有效照射区231的外轮廓一般是第一有效照射区231的光照强度最弱的位置。当I≥45时，第一有效照射区231的光照强度最弱的位置的照度都能达到最强照度的45％。此时，第一有效照射区231的整体照度较高，中心与外轮廓的亮度差异较小。这对于显示模组用于诸如投影仪的应用场景是有利的，例如类保证投影仪投射画面的亮度均一性。在更具体的实施例中，M的范围是45≤I≤70，例如，I＝50。一般来说，如果光照强度最弱的位置的照度都能达到最强照度的70％，则显示画面的亮度均匀性已经处于较高的水平，从节约成本的角度考虑，一般设计I小于或等于70。
所述第一透镜110和所述第二透镜120配置成，使得所述第一有效照射区231覆盖所述显示区131，并且，在所述显示面板130的入光面 135所在的平面上，穿过所述显示区的中心点132的任一直线(如图2中的直线260)被所述第一有效照射区231的外轮廓截取为第一线段261，并被所述显示区131的外轮廓截取为第二线段262，其中所述第一线段261与所述第二线段262的长度之比在1-1.3范围内。
通过对第一透镜110和第二透镜120进行上述配置，光源105发出的光在显示面板130上形成的第一照射区221中的有效部分(即光照强度达到最大光照强度的I％的部分，也就是第一有效照射区231)覆盖显示区131。这样，首先可以确保显示区131中显示的图像可以被完整地、实质地投射出去。同时，由于所述第一线段261与所述第二线段262的长度之比在1-1.3范围内，因此第一有效照射区231的轮廓与显示区131的外轮廓的形状与尺寸都非常的接近。这意味着，显示模组将具有较高的亮度和较高的光学效率。当第一线段261与第二线段262的长度之比小于1时，显示区不能完全地得到有效照射，导致显示区中的亮度均匀性没有达到预期。当第一线段261与第二线段262的长度之比大于1.3时，光源发出的光会有较多部分位于显示区之外，光源发出的光未被有效利用。优选地，第一线段261与第二线段262的比例可以是1.1到1.3之间，例如1.1，1.13，1.15，1.17，1.19，1.2，1.22，1.24，1.26，1.28，1.29，1.3，第一线段261与第二线段262的比例在此范围内可以使第一有效照射区231的外轮廓与显示区131之间留有一定间距，在保证光源发出光的利用效率的同时，给出足够的设计富余量。在一些实施例中，显示区131的法线与第二透镜120的光轴之间是平行的。在一些实施例中，显示区131的法线与第二透镜120的光轴之间可以存在一定的角度，例如可以在大于0°且小于等于10°的范围之内，第一线段261与第二线段262的比例在1.1到1.3之间，可以保证在显示区131的法线与第二透镜120的光轴之间存在一定的角度时，第一有效照射区231的外轮廓的外轮廓仍然包围显示区131，保证了显示效果。显示区131的法线与第二透镜120的光轴之间的角度例如可以是5°。
在一些实施例中，在所述显示面板入光面所在平面上，所述第一线段261的长度与所述第二线段262的长度的差在0-30mm范围内。当长度差在该范围内时，可认为第一有效照射区231的轮廓与显示区131的外轮廓的形状与尺寸是比较接近的，光源发出的光线被有效利用。 在一些实施例中，第一线段261可以比第二线段262长15mm-30mm，例如第一线段261可以比第二线段262长15mm，16mm，19mm，20mm，22mm，25mm，27mm，29mm，30mm。第一线段261与第二线段262的长度差在此范围内可以使第一有效照射区231的外轮廓与显示区131之间留有一定间距，在保证光源发出光的利用效率的同时，给出足够的设计富余量。在一些实施例中，显示区131的法线与第二透镜120的光轴之间是平行的。在一些实施例中，显示区131的法线与第二透镜120的光轴之间可以存在一定的角度，例如可以在大于0°且小于等于10°的范围之内，第一线段261与第二线段262的比例在1.1到1.3之间，可以保证在显示区131的法线与第二透镜120的光轴之间存在一定的角度时，第一有效照射区231的外轮廓的外轮廓仍然包围显示区131，保证了显示效果。显示区131的法线与第二透镜120的光轴之间的角度例如可以是5°。
图3示意性地示出了根据本申请实施例的显示模组的第二透镜光照效果图。在一些实施例中，所述第二透镜120包括第二入光面610和第二出光面620。第二光束220照射到第二透镜120的第二入光面610，并从第二入光面610进入到第二透镜120内，然后从第二透镜120的第二出光面620离开第二透镜120。在一些实施例中，第二透镜120可以是菲涅尔透镜，其一个表面为平面，另一个表面刻有多个同心圆，其中该平面可以作为第二透镜120的第二入光面610，该刻有多个同心圆的表面可以作为第二透镜120的第二出光面620。
所述第二入光面610所在的平面上包括第二照射区222。所述第二照射区222包括第二有效照射区232。所述第二有效照射区232被所述第二透镜在所述显示面板所在平面上映射为所述第一有效照射区231。也即，第二有效照射区232可以通过对照射到第一有效显示区231的光线进行光学追迹确定。所述第二透镜220配置成，使得所述第二有效照射区232的面积是所述显示区131的面积的90％-110％。如图3所示，第二有效照射区232的面积与显示区131的面积接近，这样，经过第二透镜120的准直后，所得到的第一有效照射区231的面积也将与显示区131的面积接近，显示模组100具有较高的光学效率，同时入射到显示区131的光学也有较好的准直性，当显示模组用于投影仪时，可以满足光学设计需要。在一个具体实施例中，第二有效照射区 232的外轮廓位于第二透镜120的第二入光面610的轮廓内；第二有效照射区232中的光在经过第二透镜120的折射后，落在显示面板所在平面上，并且这些光形成第一有效照射区。
另外，既然第二有效照射区232的面积与显示区131的面积接近，在选择第二透镜120时，可以参照显示区131的尺寸进行选择，例如，使得第二透镜120的尺寸与显示区131的尺寸接近，甚至一致。第二透镜120的尺寸与显示区131的尺寸接近，例如可以认为第二透镜120可以是显示区131等比例放大或缩小设计的，且第二透镜120的面积是显示区131的面积的90％-120％范围内，例如，第二透镜120的面积是显示区131的面积的90％，95％，100％，105％，或110％。
需要说明的是，第二入光面610接收的至少部分光由第二光束220贡献。在一些实施例中，第二入光面610入光面接收的大部分或全部的光由第二光束220贡献。
应理解，若第二透镜120的准直效果越好，则意味着第三光束230的有效发散半角γ越小。然而，即使γ角再小，也无法达到0°，这可以基于光学拓展量的理论来解释。如公式(1)所示，光学拓展量U是光束通过光学系统时的光束面积和光束角的积分。
U＝n 2∫∫cosθdAdΩ    (1)
其中，dA为面积元，θ为面积元与光源的夹角方向上发出光线，n为折射率，U为光学拓展量，Ω为光束立体角。根据这一理论可知，既不存在点光源即面积为0的光源，也不存在完全准直光源即光束角为0°的光源。即使是激光光源，也存在较小的光束角。因此，显示面板的入光面所在平面上的第一有效照射区231的面积可以大于第二透镜上的第二有效照射区232的面积。不过，正如前文提到的，第一有效照射区231的外轮廓与显示区131的外轮廓的形状与尺寸的接近，在此基础上进一步要求第二有效照射区232的面积与显示区131的面积接近，这样第一有效照射区231的面积也将与第二有效照射区232的面积接近，说明第二透镜120具有很好的准直性能。
在一个具体实施例中，第一有效照射区231的外轮廓边的数量与显示区131外轮廓边的数量相同。例如，第一有效照射区231与显示区131都为矩形。
在一个具体实施例中，第二透镜的光轴与显示面板的法线平行，第一有效照射区231的外轮廓的每一条边分别与显示区131的对应的一条边平行。例如，第一有效照射区231的外轮廓对显示区131包络设置。
在一个具体实施例中，第二透镜的光轴与显示面板的法线不平行时(例如存在5°夹角)，由于倾斜照射的缘故，第一有效照射区231的外轮廓可以为梯形，显示区131的外轮廓为矩形；梯形的长边与短边分别与显示区131的两条边平行；梯形的腰与显示区外轮廓的另外两条边都具有夹角；例如，两个夹角的度数相等。
为了使照明设备100具有较高的光学效率，可以针对显示区131的形状来选择透镜和光源的形状。在一些实施例中，所述发光区106的外轮廓与所述显示区131的外轮廓形状相同。图4示意性地示出了发光区的外轮廓的形状与显示区的外轮廓的形状的对应关系。例如，当显示区131的外轮廓的形状为矩形时，选择光源时应使光源105的发光区106也具有矩形的外形。类似的，如果显示区131的外轮廓的形状为其它多边形，则光源也应具有对应的外形。在一些实施例中，所述发光区106的外轮廓的边的数量与所述显示区131的边的数量相同，并且所述发光区106的外轮廓的每一条边在所述显示面板130上的正投影分别与所述显示区131的对应的一条边平行。例如，如图4所示，以矩形的显示区131和发光区106为例，发光区106在显示面板上的正投影1061也是矩形，并且该矩形正投影的每一条边都与显示区131的对应的一条边平行。例如，正投影1061的长边与显示区131的长边平行，正投影1061的短边与显示区131的短边平行。进一步优选地，所述发光区106的外轮廓的尺寸比例与显示区的外轮廓的的尺寸比例相同；例如，所述发光区106的外轮廓为长宽比为3∶2的矩形，显示区的外轮廓的的外轮廓也为长宽比为3∶2的矩形。
在一些实施例中，第一透镜110可以是平凸透镜。图5示意性地示出了根据本申请实施例的显示模组的第一透镜的立体图。如图5所示，第一透镜包括第一入光面510和第一出光面520。所述第一入光面510配置成接收所述第一光束。所述第一出光面520配置成向所述第二透镜120发射所述第二光束。例如，所述第一入光面510是平面，所述第一出光面520是曲面。如图5所示，第一入光面510和第一出光面 520缝合后形成第一透镜110。所述第一出光面520可以通过将一些特殊的曲线包络缝合成曲面来构造。因此，所述第一出光面520的曲面形状可以通过其上一些特殊曲线的形状来描述。图5也是这些曲线的包络图。下面分别对这些曲线进行描述。
图6示意性地示出了用于缝合成第一出光面的特殊曲线之一。所述发光区106的中心点作为原点，以所述发光区106的一条对角线所在的直线作为x轴，以所述发光区的中心法线作为y轴定义第一坐标系(X 1OY 1)。需要说明的是，发光区106的中心点应当理解为是发光区的外轮廓圈出的平面区域的几何中心。例如，发光区106的面型为曲面(如发光区106的内部向靠近第一透镜110凸出或者远离第一透镜110一侧凸出)，此时，发光区106的中心点为是发光区的外轮廓圈出的平面区域的几何中心，即几何中心不在发光区106的表面。
在一个具体实施例中，发光区106的外轮廓为矩形。需要说明的是，矩形可以包括圆角矩形，即矩形的四角中至少有一个为圆角。
图7示意性地示出了第一坐标系中光源发出的射线的光路图。图7中的光源是平面光源。如图7所示，在所述第一坐标系(X 1OY 1)内，所述光源105向所述第一透镜110发出的第一射线710被所述第一入光面510折射为第二射线720。所述第二射线720被所述第一出光面520折射为第三射线730。在确定上述三条射线时，将光源发光区106和第一透镜110的第一入光面510分成n份。每份发光区106和第一入光面510一一对应，保证光线的完整映射。所述第一出光面520的有效出光区被所述第一坐标系截成第一截线521。
在一些实施例中，对于光源来说，大角度的出射光的光强往往小于小角度的出射光的光强，因此角度过大的出射光不能被有效利用。例如，如果认为只有发光区106发出的光强度达到其发出的最大出光强度的J％的光才能满足显示要求，且所述第一光束的有效发散半角α对应于所述最大强度的J％的光，则发光区106发出的有效发散半角α以内的光在进入第一透镜110后，在第一出光面520上映射的位置所限定的区域就是第一出光面520的有效出光区。也即，第一出光面520的有效出光区可以通过对发光区106发出的大于或等于最大出光强度的J％的光进行光学追迹得到。具体地，J≥45；可选地，J的取值范围可以为45-70，可以显示画面均匀性的同时减少工艺难度，降低成本。 例如，J＝50。
在一个具体实施例中，J的值与I的值相等或近似相等。
在一些实施例中，第一出光面520的有效出光区也可以通过有效发散半角α进行定义，即可以认为发光区106发出的光中，只有发散半角小于或等于有效发散半角α的光照射到第一出光面520上的区域为第一出光面520的有效出光区。也即，第一出光面520的有效出光区可以通过对有效发散半角α以内的光进行光学追迹得到。具体地，α≤65°；可选地，α的取值范围可以为40°-65°，可以显示画面均匀性的同时减少工艺难度，降低成本。有效地，例如，α＝60°。
进一步地，如图13所示，对于发光区106的轮廓上且与发光区106的一条对角线交界的两点，以第一光束210的有效发散半角α发射的向外侧扩散光线在第一透镜110以β角折射，并在第二透镜120处以γ角折射，然后投射到显示面板131所在平面。具体地，β角的取值范围可以是：25°≤β≤45°；γ角的取值范围可以是：0°≤γ≤10°。
进一步地，如图13所示，G是发光区106与第一透镜110之间的距离，h是第二入光面510与发光区106之间的距离.
当α、β、γ、h、G以及发光区106外轮廓坐标确定时，则第一截线521的线性可以确定。
所述第一截线521上的任意一点(x 1，y 1)满足下述方程：
Figure PCTCN2022099958-appb-000006
其中，h是所述第二透镜120的第二入光面610与所述发光区106之间的距离(如图13所示)。G是所述发光区106与所述第一入光面510之间的距离。所述第二透镜120包括第二入光面610。光源从发光区106的O点(O ix1，O 0)发出光，照射到第一透镜110的第一入光面510上的S点(S ix1，S iy1)，并从S点进入第一透镜110内。该光然后从第一出光面520上的P点(P ix1，P iy1)出射离开第一透镜110，并照射到第二透镜120的第二入光面610上的T点(T ix1，T iy1)。因此，S ix1是所述第一射线710与所述第一入光面510的交点到所述发光区106的中心法线的距离。T ix1是所述第三射线730与所述第二入光面610 的交点到所述发光区106的中心法线的距离。为了保证在加工和安装过程中的便利性，第一透镜110的第一入光面510是平面，所以第一入光面510在第一坐标系(X 1OY 1)上的截线是一条平行于发光区106的直线y 1＝G。因此S iy1＝G。类似的，第二透镜120的第二入光面610也是平面，因此T iy1＝h。第一射线710、第二射线720和第三射线730分别与y轴(也就是发光区106的中心法线)成α i1、θ i1角、和β i1角。也就是，β i1是所述第三射线730与所述发光区106的中心法线之间的夹角，θ i1是所述第二射线720与所述发光区106的中心法线之间的夹角。M和N是常数，其中0≤M≤4，0≤N≤4。在更具体的实施例中，M约等于1，N约等于1。在一些实施例中，M和N取决于透镜加工公差、曲面归一化误差、和曲面拟合误差的常数，M和N可以用来调控第一截线的顶点的位置。当M大于4时或当N大于4时，可能导致所得到的第一截线不可用。在最理想的情况下，M＝0且N＝0。需要说明的是，当发光区106面型为曲面时，h为发光区106外轮廓圈出平面区域的几何中心与所述第二透镜120的第二入光面610之间的距离。另外，当发光区106面型为曲面时，G为发光区106外轮廓圈出平面区域的几何中心与所述第一透镜110的第一入光面510之间的距离。
下面简单介绍第一截线521的方程的原理。首先计算经过第一透镜的有效出光区内的任一光线的直线方程。根据图7可得出，OS光线(即第一射线710)在X 1OY 1直角坐标系下的通用方程为：
y 1＝tan(90°-α i1)x 1-O ix1tan(90°-α i1)      (3)
SP光线(即第二射线720)在X 1OY 1直角坐标系下的通用方程为：
y 1＝tan(90°-θ i1)x 1+[G-tan(90°-θ i1)·S ix1]      (4)
PT光线(即第三射线730)在X 1OY 1直角坐标系下的通用方程为：
y 1＝tan(90°-β i1)x 1+[T iy1-tan(90°-β i1)·T ix1]      (5)
根据斯涅尔(Snell)定律(即，折射定律)，可得到α i1和θ i1角之间的关系。
sinα i1·n 1＝sinθ i1·n 2      (6)
在公式(6)中，n 1为第一透镜110外的介质(例如，空气)的折射率，n 2为第一透镜110的材料的折射率。
接下来，计算P点的切线方程。图8示意性地示出了第一透镜的第一出光面的切线。根据图8可知，P点的切线方程为：
y 1＝tan(-u 1)·x 1+P iy1-P ix1·tan(-u 1)      (7)
其中，
u i1＝δ i1+θ i1      (8)
u i1＝β i1+δ i2      (9)
n 1sinδ i1＝n 2sinδ i2      (10)
通过对上述各公式进行多次迭代，可以得到第一截线521上的点集。通过拟合点集，可以求出第一截线521的参数，最终计算出第一截线521的方程为前述公式(2)所表示的方程。第一出光面520的沿发光区106的另一条对角线所在坐标系的截线可以通过类似推导或者镜像关系得到，在此不再赘述。
图9示意性地示出了用于缝合成第一出光面的特殊曲线之二。以发光区106的中心点作为原点，以所述发光区106外轮廓的长边的延伸方向作为x轴的方向，以所述发光区的中心法线作为y轴定义第二坐标系(X 2OY 2)。与前述相同，发光区106的中心点应当理解为是发光区的外轮廓圈出的平面区域的几何中心。发光区102的外轮廓例如为矩形。
在第二坐标系内，光源发出的射线也会得到与图7类似的光路图，在此不再赘述。在所述第二坐标系内，光源向第一透镜110发出的第一射线被所述第一入光面510折射为第二射线。所述第二射线被所述第一出光面520折射为第三射线。所述第一出光面520的有效出光区被所述第二坐标系截成第二截线522。第一出光面520的有效出光区的定义与描述特殊曲线之一时的定义相同。
所述第二截线522上的任意一点(x 2，y 2)满足下述方程：
Figure PCTCN2022099958-appb-000007
其中，h是所述第二入光面与所述发光区之间的距离，G是所述发光区与所述第一入光面之间的距离，S ix2是所述第一射线与所述第一入光面的交点到所述发光区的中心法线的距离，T ix2是所述第三射线与所述第二入光面的交点到所述发光区的中心法线的距离，β i2是所述第三射线与所述发光区的中心法线之间的夹角，θ i2是所述第二射线与所述发光区的中心法线之间的夹角，P和Q是常数，其中0≤P≤3，0≤Q≤3。在更具体的实施例中，P约等于1，Q约等于1。在一些实施例中，P和Q取决于透镜加工公差、曲面归一化误差、和曲面拟合误差。P和Q可以用来调控第二截线的顶点的位置。对于矩形平面光源来说，其长边的长度小于其对角线的长度。因此，第二截线的误差比第一截线的误差更小，所以P和Q的值例如比M和N的值小。当P大于3时或当Q大于3时，可能导致所得到的第二截线不可用。
图10示意性地示出了用于缝合成第一出光面的特殊曲线之三。以发光区106的中心点作为原点，以所述发光区106外轮廓的短边的延伸方向作为x轴的方向，以所述发光区的中心法线作为y轴定义第三坐标系(X 3OY 3)。发光区102的外轮廓为矩形。与前述相同，发光区106的中心点应当理解为是发光区的外轮廓圈出的平面区域的几何中心。
在第三坐标系内，光源发出的射线也会得到与图7类似的光路图，在此不再赘述。在所述第三坐标系内，光源向第一透镜110发出的第一射线被所述第一入光面510折射为第二射线。所述第二射线被所述第一出光面520折射为第三射线。所述第一出光面520的有效出光区被所述第三坐标系截成第三截线523。第一出光面520的有效出光区的定义与描述特殊曲线之一时的定义相同。
所述第三截线523上的任意一点(x 3，y 3)满足下述方程：
Figure PCTCN2022099958-appb-000008
其中，h是所述第二入光面与所述发光区之间的距离，G是所述发光区与所述第一入光面之间的距离，S ix3是所述第一射线与所述第一入光面的交点到所述发光区的中心法线的距离，T ix3是所述第三射线与所述第二入光面的交点到所述发光区的中心法线的距离，β i3是所述第三射线与所述发光区的中心法线之间的夹角，θ i3是所述第二射线与所述发光区的中心法线之间的夹角，C和V常数，其中0≤C≤2，0≤V≤2。在更具体的实施例中，C约等于1，V约等于1。在一些实施例中，C和V取决于透镜加工公差、曲面归一化误差、和曲面拟合误差。对于矩形平面光源来说，其短边的长度小于其长边的长度。因此，第三截线的误差比第二截线的误差更小，所以C和V的值一般比P和Q的值小。当C大于2时或当V大于2时，可能导致所得到的第三截线不可用。
需要说明的是，对于同一个第一透镜，决定公式(2)、(11)、(12)的
在更具体的实施例中，光源的发光区106的外轮廓为矩形的长为13mm，宽为9mm。显示面板的显示区131的长为101mm、宽为58mm。所述发光区106与所述第一入光面510之间的距离G是2mm。第二透镜的第二出入面610与液晶面板的距离L是8mm。所述第二入光面的与所述发光区之间的距离h为78mm，选择α＝60°，β＝35°，γ＝10°。在这种情况下，可以利用公式(2)、(11)、(12)得到三条截线各自的点集。通过对每条截线的点集拟合成曲线，并设定曲线的最高次幂(例如，可以设最高次幂为3)，可以分别得到第一截线521的曲线方程是：
y 1＝-0.0013x 1 3-0.0056x 1 2-0.0427x 1+21      (13)
第二截线522的曲线方程是：
y 2＝0.0029x 2 3-0.0484x 2 2+0.0357x 2+21      (14)
第三截线523的曲线方程是：
y 3＝-0.0019x 3 3+0.0046x 3 2-0.0599x 3+21      (15)
最高次幂的具体数值取决于点集的计算结果和曲线贴合度。例如，在前述公式(13)-(15)中，当最高次幂取3次时，所拟合的曲线与点集组成的曲线更加贴合，因此将最高次幂设定为3次。取决于点集的不同，不排除曲线的最高次幂为其它数值，例如4次幂。
在得到了上述第一截线521、第二截线522、第三截线523、以及第一截线的镜像截线后，可以通过这四条曲线得到第一出光面520的曲面。例如，将四条曲线导入到处理软件中，通过缝合曲面命令，将曲线包络图(例如图5)缝合成曲面啮合图。由于上述四条曲线是点集拟合出的曲线，所以这四条曲线可能出现顶点不相交的情况，导致出现曲线包络出错。在这种情况下，需要通过调整M、N、P、Q、C、V等值来对曲线进行微调，保证顶点相交。图11示意性地示出了根据本申请实施例的显示模组的第一透镜的第一出光面的曲面拟合图。
在曲面拟合完成后，根据所需要的外形和所述发光区与所述第一入光面之间的距离G的值，设计第一透镜110的底座111位置。然后将底座与拟合曲面进行缝合，以得到第一透镜110的结构。图12示意性地示出了经过缝合后的第一透镜的结构图。通过上述公式拟合出的第一透镜具有优异的光学性能，能够用于使第一有效照射区231的外轮廓的形状和面积接近与显示区131的外轮廓的形状和面积，提高了显示模组110的光学效率。
在一个具体实施例中，进入显示区131的光线的至少部分光线是发光区106发出的光经过第一透镜110和第二透镜120形成的，这些光线可以通过追迹的方式在第一出光面520划定一个连续分布的区域，定义为有效投射区。可以理解的是，所述有效投射区位于有效出光区内；有效投射区被所述第一坐标系截成的第四截线位于第一截线521内，且第四截线上的任意一点满足式(2)方程；有效投射区被所述第二坐标系截成的第五截线位于第二截线522内，且第五截线上的任意一点满足式(11)方程；有效投射区被所述第三坐标系截成的第六截线位于第三截线523内，且第六截线上的任意一点满足式(12)方程。
根据前述公式(2)、(11)、(12)可以看出，第一透镜110的 曲面结构与所述第二入光面610与所述发光区106之间的距离h相联系。下面将介绍确定距离h的方法。
图13示意性地示出了根据本申请实施例的显示模组的光路图，示意角度为沿着发光区106的一条对角线方向，与图7视角相同。通过图中的尺寸与角度关系，可以得到所述第二入光面610与所述发光区106之间的距离h满足下述公式：
Figure PCTCN2022099958-appb-000009
其中，显示区131的外轮廓和发光区106的外轮廓都是矩形，A是所述显示区131的对角线长度，B是所述发光区106的对角线长度，G是发光区106与所述第一透镜110之间的距离；L是所述显示区131的入光面的中心点与所述第二透镜120的第二入光面610的中心点之间的距离。α是所述第一光束210的有效发散半角。其中，发光区105的轮廓上以第一光束210的有效发散半角α发射的光线在第一透镜110以β角折射，并在第二透镜120处以γ角折射。定义β是所述第二光束220的有效发散半角，定义γ是所述第三光束230的有效发散半角。K是常数，K的取值范围在-5mm到5mm的范围内。优选地，K的取值范围在0-2mm的范围内。进一步优选地，K的取值范围在0-1mm的范围内。
第二光束220的有效发散半角β反映了第一透镜110的会聚能力。在透镜设计时，可以选择第一透镜110的材料和表面形状来决定β。在第一光束的有效发散半角α不变的情况下，第一透镜110的会聚能力越强，则第二光束220的有效发散半角β越小。
第三光束230的有效发散半角γ反映了第二透镜120的会聚能力。在透镜设计时，可以选择第二透镜120的材料和表面形状来决定γ。第二透镜120的会聚能力越强，则第三光束230的有效发散半角γ越小。
K可以取决于装配公差和加工公差。具体的，K的值可以参考显示模组内的元器件的装配情况，以及各个元器件之间的误差。K的取值范围在-5mm到5mm范围内，可以保证较好的成像质量。通过代入这些量，可以得到第二入光面610与发光区106之间的距离h。基于第二入光面610与发光区106之间的距离h，可以确定第二透镜120的安装 位置。
在一些实施例中，所述显示区131的对角线长度A的范围是10mm≤A≤200mm。在更具体的实施例中，5.8mm≤A≤150mm。例如，在可得的4.45寸显示面板中，对角线长度A＝114mm。
在一些实施例中，所述发光区106的对角线长度B的范围是2mm≤B≤20mm。发光区106的尺寸在此范围内的光源也是容易得到的。例如，常用的LED管芯的尺寸为2mm，而大发光面光源的尺寸为20mm。在更具体的实施例中B＝15.8mm。
在一些实施例中，所述发光区106与所述第一透镜110之间的距离G的范围是1mm≤G≤3.5mm。具体地，为便于散热，光源105与所述第一透镜110之间需要留有至少1mm的间距；而当G变大时，需要增加第一透镜110的尺寸以有效接收光照，不利于显示模组的紧凑设计。在更具体的实施例中，G＝2mm可以兼顾散热和模组尺寸，并达到很好的光学效果。
在一些实施例中，h的范围满足：50mm≤h≤150mm。当h大于150mm时，显示模组的体积过大，不具有适用性。当h小于50mm时，可能导致光效降低的情况。
在一些实施例中，可以在合适的范围内直接选取显示区131的入光面的中心点与第二透镜120的第二入光面610的中心点之间的距离L的值。距离L的取值范围可以是6mm-16mm。在该范围内，第二透镜120更容易装配，且散热性能良好。当L小于6mm时，显示区131与第二透镜120之间的风道过窄，无法充分散热。当L大于16mm时，风压会降低，导致散热效果下降。在更具体的实施例中，距离L可以是9mm或11mm。
在一些实施例中，第二透镜120的焦距F可以根据第二入光面610与发光区106之间的距离h来确定。图14示意性地示出了第二透镜的焦距的计算原理图。当光线经过透镜时，在透镜中心做入射光线的平行线，该平行线与出射光线的交点向光轴作垂线，垂足位置为透镜的焦点F。从图14中可以得到，第二透镜120的焦距F满足下述公式：
Figure PCTCN2022099958-appb-000010
其中，A是所述显示区的对角线长度，h是第二入光面510与发光区106之间的距离，G是发光区106与第一透镜110之间的距离，E是常数，其中，-2.5＜E≤2.5。具体地，在公式(17)中，常数E考虑了第二透镜120的加工公差以及取整公差。由于F值计算出后可能会有不取整的情况，考虑到设计的便利性，所以要使F可以被5整除，此时可以用E来调配。例如调配方式可以是将F调整为与
Figure PCTCN2022099958-appb-000011
最接近的可被5整除的数，接近程度相同时，取更大的焦距(例如计算
Figure PCTCN2022099958-appb-000012
时，调整为75mm)。在一些实施例中，F值可以只满足是整数即可，在此实施例中，-0.5＜E≤0.5，也即，在计算得到
Figure PCTCN2022099958-appb-000013
后，采用四舍五入的方法使F值为整数。在一些实施例中，F值也可以不为整数。需要说明的是，实际测量的第二透镜120的焦距与上述计算值的差值在+/-5mm以内，均属于本申请的公开范围。
在一些实施例中，根据显示区131的尺寸，第二透镜120的焦距F可以在50mm-200mm的范围内取值，这主要取决于所适用的显示面板的尺寸。
为了计算简便，在第二透镜120的焦距F的计算中，将第二透镜120理解为理想的透镜，即厚度为0的透镜。但在实际使用中，第二透镜120的厚度不可能制作成0。为了减小第二透镜120的厚度，在一些实施例中，第二透镜120可以是菲涅尔透镜。但即使这样，菲涅尔透镜仍然具有厚度，菲涅尔透镜的厚度可以在1.5mm-2mm范围内。菲涅尔透镜的一个表面为平面，另一个表面刻有多个同心圆，其中该平面可 以作为第二透镜120的第二入光面610，该刻有多个同心圆的表面可以作为第二透镜120的第二出光面620。在进行上述计算时，以该平面作为定位平面，即，确定所述显示区与所述第二透镜的距离时，以所述显示区的入光面的中心点与所述第二透镜的第二入光面的中心点之间的距离作为衡量对象。图15示意性地示出了根据本申请实施例的显示模组在显示面板131上形成的第一照射区的照度分布。其中，区域136示意性地示出了显示区131的外轮廓的位置。如图15所送，显示区131的外轮廓136上的任一点的照度都大于或等于显示区131内照度最大点的照度的50％，而且整个显示区的照度都大于最大照度的50％，达到了很好的显示效果。
图16示意性地示出了可用于本申请实施例的示例性光源的照度分布图。从图16可以看出，光源发出的光束(例如第一光束210)的照度与有效发散半角α(也就是光源的有效发散角为2α)有关。根据图16可以看到，第一光束210的有效发散半角α与光源的边缘光线的照度有关系。以图16所针对的光源为例，随着第一光束210的有效发散半角增大，光源的边缘光线的照度与光源的中心光线的照度的百分比逐渐下降。在一些实施例中，所述第一光束的有效发散半角α的范围是40°≤α≤65°。在显示模组选用了图16所代表的光源的情况下，如果需要边缘光线照度达到最大照度的至少50％，则可以将α设置为60°。
前面还提到，第二透镜120的准直效果越好，则意味着第三光束230的有效发散半角γ越小，然而即使γ角再小，也无法达到0°。在显示模组用于投影仪时，可以接受γ角不超过10°。
第二光束220的有效发散半角β应取介于α和γ之前。可选地，β的取值范围在25°-45°范围内，以提升从第二透镜出射的光的准直性。优选地，β的取值范围在30°-40°范围内；进一步优选地，优选地，β＝35°。在一些实施例中，β＝(α+γ)/2，在便于设计的同时达到较好的出光效果。
在一些实施例中，所述显示面板130是液晶显示面板。液晶显示面板的显示区131用于显示画面。液晶显示面板的显示区131例如为矩形。
图18示意性地示出了根据本申请实施例的显示模组的截面图。如 图18所示，在一些实施例中，所述显示模组100还包括第一反射镜140。所述第一反射镜140位于所述第一透镜110的光学下游和所述第二透镜120的光学上游。术语光学下游是指光行进的方向。因此，第一透镜110发出的光将照射到第一反射镜140。术语光学上游是指光的来源方向。因此，第一反射镜140反射的光，也就是第一透镜110发出的光被第一反射镜140反射到第二透镜120上。因此，所述第一反射镜140被配置成将所述第二光束220从所述第一透镜110定向到所述第二透镜120。在一些实施例中，第一反射镜140的法线可以与第二透镜120的光轴成45°角。通过设置第一反射镜140，在光程不变的情况下，通过使光束改变行进方向，可以减少显示模组100在至少一个维度上的尺寸。
需要说明的是，当显示模组100还包括第一反射镜140时，第二入光面610与发光区106之间的距离h可以理解为发光区106沿过发光区106中心的法线方向发出的光经过第一反射镜140反射后到达第二透镜120的入光面的总路径长度。当发光区106面型为曲面时，发光区106中心发出的光视为从发光区106的外轮廓圈出的平面区域的几何中心发出的。
在一些实施例中，可以基于软件模拟结果对显示模组的结构进行微调。图19A和19B示意性地示出了根据本申请实施例的显示模组的发光效果的软件模拟图。例如，上述实施例中所描述的光源、第一透镜、第二透镜的参数被输入到仿真软件中，光源、第一透镜、第二透镜与显示面板之间的距离也输入到仿真软件中进行分析，通过选定发光角度和光线数量，可以对照度和光通量分析。基于照度分布图，可以不断优化透镜的参数(例如透镜的表面结构)，直到达到需求参数，以确定显示模组的最终结构。
综上所述，根据本申请实施例的发光结构可以将光源发出的光完全入射到显示面板上，并使得光源在显示面板上映射的有效显示区的外轮廓形状与面积限定为接近显示区的外轮廓形状和面积，从而提高了光学效率，并且还使得发出的光具有符合要求的角点均一性。
除了上述显示模组的结构自身，本申请还提供了一种设计显示模组的方法。通过该方法，可以设计出根据本申请实施例的显示模组。该方法可以用于设计具有光源、第一透镜、第二透镜、和显示面板的显 示模组，其中第一透镜和第二透镜位于光源和显示面板之间，第一透镜相对于第二透镜更靠近光源，第二透镜相对于第一透镜更靠近显示面板。该方法可以在已知光源和显示面板的尺寸的情况下设计第一透镜和第二透镜的参数以及这些元件之间的位置关系，以实现前面描述的各种光学效果。具体的，在该设计方法中，首先基于照明设备的散热需求(也就是照明设备需要的足以支持散热的通风空间)，确定显示面板与第二透镜的距离。然后，基于显示面板与第二透镜的距离、显示面板的显示区与光源的发光区的尺寸、以及第一透镜与光源的距离，确定光源与第二透镜的距离。然后，基于光源与第二透镜的距离和显示面板的尺寸确定第二透镜的焦距。在得到这些参数后，可以依据前文的公式确定第一透镜的出光面上的一些特殊曲线的方程，并用这些曲线拟合为曲面，以得到第一透镜的出光面的曲面形状。然后，为第一透镜提供底座，并利用仿真软件进行调试，以得到第一透镜的实体结构。
根据本申请的另一方面，提供了一种投影仪。图21示意性地示出了根据本申请实施例的投影仪的截面图。所述投影仪200包括根据本申请任一实施例的显示模组100。如图21所示，投影仪200还包括第三透镜300和投影透镜400。第三透镜300位于所述显示模组100的光学下游，所述投影透镜400位于所述第三透镜300的光学下游。第三透镜300可以对显示面板130显示的画面进行初次成像，使画面成正立虚像，并将显示面板130出射的光线进行会聚，以便减小镜头孔径。在一些实施例中，第三透镜300可以是菲涅尔透镜。投影透镜400可以放大成像、改善像差。
在一些实施例中，所述投影仪200还包括第二反射镜500。第二反射镜500配置成将所述第三透镜300发出的光反射到所述投影透镜400。在一些实施例中，第二反射镜500的法线可以与第三透镜300的光轴呈45°夹角。根据本申请实施例的投影仪可以具有根据本申请实施例的显示模组的所有优点和效果，在此不再赘述。
发明人对本申请实施例的投影仪的光学性能进行了测试，其中该投影仪内包含本申请实施例所述的显示模组。图20示意性地示出了根据本申请实施例的投影仪的照度测试图。如图20所示，投影仪投射的画面被分割为9份，测量时测量每一份的中心部位(例如图20中的圆圈 位置)的照度。测量设备为柯尼卡美能达CL-200A型色彩照度计。经测试，投影画面的照度均匀度为61.2％，整体设计符合要求。
在本申请实施例的描述中，通过术语“上”、“下”、“左”、“右”等指示的方位或位置关系基于附图所示的方位或位置关系，其仅是为了便于描述本申请的实施例，而不要求这些实施例必须以特定的方位构造和操作，因此不能理解为对本申请的限制。
在本申请的描述中，诸如“一些实施例”、“另一些实施例”等术语意指结合该实施例描述的具体特征、结构、材料或者特点被包含于本申请的至少一个实施例中。说明书中对上述术语的示意性表述不必须针对的是相同的实施例或示例。而且，所描述的具体特征、结构、材料或者特点可以在任一个或多个实施例或示例中以合适的方式结合。此外，在不相互矛盾的情况下，本领域的技术人员可以将本申请中描述的不同实施例或示例以及这些实施例或示例的特征进行结合。另外，需要说明的是，本申请中，术语“第一”、“第二”或类似术语仅用于描述或命名的目的，而不能理解为指示或暗示相对重要性或者指明所修饰的技术特征的数量。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此。任何熟悉本技术领域的技术人员在本申请公开的技术范围内，可轻易想到的变化或替换，都应涵盖在本申请的保护范围之内。

Claims (26)

  1. 一种显示模组，包括光源、第一透镜、第二透镜、和显示面板，
    其中，所述光源包括发光区，所述显示面板包括显示区，
    所述光源配置成通过所述发光区向所述第一透镜发射第一光束，
    所述第一透镜配置成接收所述第一光束、将所述第一光束折射成第二光束、以及向所述第二透镜发射所述第二光束，
    所述第二透镜配置成接收所述第二光束、将所述第二光束折射成第三光束、以及向所述显示面板发射所述第三光束；
    其中，所述显示面板的入光面所在平面上包括第一照射区，所述第一照射区包括连续分布的第一有效照射区，所述第一有效照射区内包括光照最强位置；所述第一有效照射区的外轮廓上的光照强度为所述光照最强位置的光照强度的I％；其中，I≥45；
    其中，所述第一透镜和所述第二透镜配置成，使所述第一有效照射区覆盖所述显示区，并且，在所述显示面板的入光面所在平面上，穿过所述显示区的中心点的任一直线被所述第一有效照射区的外轮廓截取为第一线段、并被所述显示区的外轮廓截取为第二线段，其中所述第一线段与所述第二线段的长度之比在1-1.3范围内。
  2. 如权利要求1所述的显示模组，其中，在所述显示面板的入光面所在平面上，所述第一线段的长度与所述第二线段的长度的差在0-30mm范围内。
  3. 如权利要求1所述的显示模组，其中，所述第二透镜包括第二入光面和第二出光面，所述第二光束在所述第二入光面所在的平面上包括第二照射区，所述第二照射区包括第二有效照射区，所述第二有效照射区被所述第二透镜在所述显示面板所在平面上映射为所述第一有效照射区，
    其中，所述第二透镜配置成，使得所述第二有效照射区的面积是所述显示区的面积的90％至110％。
  4. 如权利要求1所述的显示模组，其中，所述发光区的外轮廓与所述显示区的外轮廓形状相同。
  5. 如权利要求1所述的显示模组，其中，所述第一有效照射区的外轮廓为梯形，所述显示区的外轮廓为矩形；所述梯形的长边与短边 分别与所述显示区的外轮廓的两条边平行；所述梯形的腰与所述显示区的外轮廓的另外两条边都具有夹角。
  6. 如权利要求1所述的显示模组，其中，所述第一透镜包括第一入光面和第一出光面，所述第一入光面配置成接收所述第一光束，所述第一出光面配置成向所述第二透镜发射所述第二光束，所述第二透镜包括第二入光面和第二出光面，所述发光区的外轮廓为矩形；
    其中，以所述发光区的中心点作为原点，以所述发光区的一条对角线所在的直线作为x轴，以所述发光区的中心法线作为y轴定义第一坐标系，
    其中，在所述第一坐标系内，所述光源向所述第一透镜发出的第一射线被所述第一入光面折射为第二射线，所述第二射线被所述第一出光面折射为第三射线，
    其中，所述第一出光面的有效出光区在所述第一坐标系上的截线是第一截线，所述第一截线上的任意一点(x 1，y 1)满足下述方程：
    Figure PCTCN2022099958-appb-100001
    其中，h是所述第二入光面与所述发光区之间的距离，G是所述发光区与所述第一入光面之间的距离，S ix1是所述第一射线与所述第一入光面的交点到所述发光区的中心法线的距离，T ix1是所述第三射线与所述第二入光面的交点到所述发光区的中心法线的距离，β i1是所述第三射线与所述发光区的中心法线之间的夹角，θ i1是所述第二射线与所述发光区的中心法线之间的夹角，M和N是常数，其中0≤M≤4，0≤N≤4。
  7. 如权利要求1所述的显示模组，其中，所述第一透镜包括第一入光面和第一出光面，所述第一入光面配置成接收所述第一光束，所述第一出光面配置成向所述第二透镜发射所述第二光束，所述第二透镜包括第二入光面和第二出光面，所述发光区的外轮廓为矩形；
    其中，以所述发光区的中心点作为原点，以所述发光区的长边的延伸方向作为x轴的方向，以所述发光区的中心法线作为y轴定义第二坐标系，
    其中，在所述第二坐标系内，所述光源向所述第一透镜发出的第一射线被所述第一入光面折射为第二射线，所述第二射线被所述第一出光面折射为第三射线，
    其中，所述第一出光面的有效出光区在所述第二坐标系上的截线是第二截线，所述第二截线上的任意一点(x 2，y 2)满足下述方程：
    Figure PCTCN2022099958-appb-100002
    其中，h是所述第二入光面与所述发光区之间的距离，G是所述发光区与所述第一入光面之间的距离，S ix2是所述第一射线与所述第一入光面的交点到所述发光区的中心法线的距离，T ix2是所述第三射线与所述第二入光面的交点到所述发光区的中心法线的距离，β i2是所述第三射线与所述发光区的中心法线之间的夹角，θ i2是所述第二射线与所述发光区的中心法线之间的夹角，P和Q是常数，其中0≤P≤3，0≤Q≤3。
  8. 如权利要求1所述的显示模组，其中，所述第一透镜包括第一入光面和第一出光面，所述第一入光面配置成接收所述第一光束，所述第一出光面配置成向所述第二透镜发射所述第二光束，其中，所述第二透镜包括第二入光面和第二出光面，所述发光区的外轮廓为矩形；
    其中，以所述发光区的中心点作为原点，以所述发光区的短边的延伸方向作为x轴的方向，以所述发光区的中心法线作为y轴定义第三坐标系，
    其中，在所述第三坐标系内，所述光源向所述第一透镜发出的第一射线被所述第一入光面折射为第二射线，所述第二射线被所述第一出光面折射为第三射线，
    其中，所述第一出光面的有效出光区在所述第三坐标系上的截线是第三截线，所述第三截线上的任意一点(x 3，y 3)满足下述方程：
    Figure PCTCN2022099958-appb-100003
    其中，h是所述第二入光面与所述发光区之间的距离，G是所述发光区与所述第一入光面之间的距离，S ix3是所述第一射线与所述第一入光面的交点到所述发光区的中心法线的距离，T ix3是所述第三射线与所述第二入光面的交点到所述发光区的中心法线的距离，β i3是所述第三射线与所述发光区的中心法线之间的夹角，θ i3是所述第二射线与所述发光区的中心法线之间的夹角，C和V是常数，其中0≤C≤2，0≤V≤2。
  9. 如权利要求6-8中任一项所述的显示模组，其中所述第一入光面是平面，所述第一出光面是曲面。
  10. 如权利要求1-8中任一项所述的显示模组，其中，所述显示区的外轮廓和所述发光区的外轮廓都是矩形，所述第二透镜包括第二入光面和第二出光面，所述第二入光面与所述发光区之间的距离h满足下述公式：
    Figure PCTCN2022099958-appb-100004
    其中，A是所述显示区的对角线的长度，B是所述发光区的对角线的长度，G是所述发光区与所述第一透镜之间的距离，L是所述显示区的入光面的中心点与所述第二透镜的第二入光面的中心点之间的距离，α是所述第一光束的有效发散半角，β是所述第二光束的有效发散半角，γ是所述第三光束的有效发散半角，K是常数，K的范围是-5mm≤K≤5mm。
  11. 如权利要求1-10中任一项所述的显示模组，其中，所述第二透镜包括第二入光面和第二出光面，所述第二入光面与所述发光区之间的距离h的范围是50mm≤h≤150mm。
  12. 如权利要求1-10中任一项所述的显示模组，其中，所述显示区的对角线的长度A的范围是10mm≤A≤200mm。
  13. 如权利要求1-10中任一项所述的显示模组，其中，所述发光区的对角线的长度B的范围是2mm≤B≤20mm。
  14. 如权利要求1-10中任一项所述的显示模组，其中，所述发光区与所述第一透镜之间的距离G的范围是1mm≤G≤3.5mm。
  15. 如权利要求1-10中任一项所述的显示模组，其中，所述第二透镜包括第二入光面和第二出光面，所述显示区的入光面的中心点与所述第二入光面的中心点之间的距离L的范围是6mm≤L≤16mm。
  16. 如权利要求1-10中任一项所述的显示模组，其中，所述第二透镜的焦距F满足下述公式：
    Figure PCTCN2022099958-appb-100005
    其中，A是所述显示区的对角线长度，h是所述第二入光面与所述发光区之间的距离，G是所述发光区与所述第一透镜之间的距离，E是常数，β是所述第二光束的有效发散半角，γ是所述第三光束的有效发散半角，其中，-2.5mm＜E≤2.5mm。
  17. 如权利要求1-10中任一项所述的显示模组，其中，所述第二透镜的焦距F的范围是50mm≤F≤200mm。
  18. 如权利要求1-10中任一项所述的显示模组，其中，所述第一光束的有效发散半角α的范围是40°≤α≤65°。
  19. 如权利要求1-10中任一项所述的显示模组，其中，所述第三光束的有效发散半角γ的范围是0°≤γ≤10°
  20. 如权利要求1-10中任一项所述的显示模组，其中，所述第二光束的有效发散半角β的范围是25°≤β≤45°。
  21. 如权利要求1-10中任一项所述的显示模组，其中，所述第一光束的有效发散半角α、所述第二光束的有效发散半角β、所述第三光束的有效发散半角γ满足下述公式：
    β＝(α+γ)/2。
  22. 如权利要求1-10中任一项所述的显示模组，其中，所述第二透镜是菲涅尔透镜，并且所述第二透镜沿光轴方向的厚度的范围是1.5mm-2mm。
  23. 如权利要求1-10中任一项所述的显示模组，其中，所述显示面板是液晶显示面板。
  24. 如权利要求1-10中任一项所述的显示模组，还包括第一反射 镜，其中所述第一反射镜位于所述第一透镜的光学下游和所述第二透镜的光学上游，并且所述第一反射镜配置成将所述第二光束从所述第一透镜反射到所述第二透镜。
  25. 一种投影仪，包括如权利要求1-24中任一项所述的显示模组、第三透镜、以及投影透镜，其中，所述第三透镜位于所述显示模组的光学下游，所述投影透镜位于所述第三透镜的光学下游。
  26. 如权利要求25所述的投影仪，还包括第二反射镜，其中，所述第二反射镜配置成将所述第三透镜发出的光反射到所述投影透镜。
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000241755A (ja) * 1999-02-18 2000-09-08 Fujitsu Ltd 照明装置及びその照度分布改善装置並びに液晶投写装置
JP2000330200A (ja) * 1998-12-08 2000-11-30 Toshiba Corp 投影光学系などの光学ユニットとその製造方法、およびこれらを備えた表示装置
US6552760B1 (en) * 1999-02-18 2003-04-22 Fujitsu Limited Luminaire with improved light utilization efficiency
US20040227910A1 (en) * 2003-01-14 2004-11-18 Seiko Epson Corporation Illumination optical device and projector
CN101097394A (zh) * 2006-06-26 2008-01-02 Nec显示器解决方案株式会社 照明光学器件和投影显示装置
CN102707553A (zh) * 2011-03-28 2012-10-03 索尼公司 照明单元、投射型显示单元以及直视型显示单元

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000330200A (ja) * 1998-12-08 2000-11-30 Toshiba Corp 投影光学系などの光学ユニットとその製造方法、およびこれらを備えた表示装置
JP2000241755A (ja) * 1999-02-18 2000-09-08 Fujitsu Ltd 照明装置及びその照度分布改善装置並びに液晶投写装置
US6552760B1 (en) * 1999-02-18 2003-04-22 Fujitsu Limited Luminaire with improved light utilization efficiency
US20040227910A1 (en) * 2003-01-14 2004-11-18 Seiko Epson Corporation Illumination optical device and projector
CN101097394A (zh) * 2006-06-26 2008-01-02 Nec显示器解决方案株式会社 照明光学器件和投影显示装置
CN102707553A (zh) * 2011-03-28 2012-10-03 索尼公司 照明单元、投射型显示单元以及直视型显示单元

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