CN116520628A - Backlight module for optical machine and projector - Google Patents
Backlight module for optical machine and projector Download PDFInfo
- Publication number
- CN116520628A CN116520628A CN202310512369.XA CN202310512369A CN116520628A CN 116520628 A CN116520628 A CN 116520628A CN 202310512369 A CN202310512369 A CN 202310512369A CN 116520628 A CN116520628 A CN 116520628A
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- form surface
- light source
- light
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- 230000003287 optical effect Effects 0.000 title claims abstract description 20
- 239000004973 liquid crystal related substance Substances 0.000 claims abstract description 24
- 230000000694 effects Effects 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 9
- 238000005286 illumination Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000005388 borosilicate glass Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 2
- 239000004926 polymethyl methacrylate Substances 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012994 photoredox catalyst Substances 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/20—Lamp housings
- G03B21/206—Control of light source other than position or intensity
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/20—Lamp housings
- G03B21/2066—Reflectors in illumination beam
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Lenses (AREA)
Abstract
The invention relates to a backlight module for an optical machine and a projector, which comprises a light source, a lens, a free-form surface reflector and a liquid crystal screen, wherein the light source is arranged on the free-form surface reflector; the light source is used for outputting light along the direction of the optical axis of the light source, the light incident surface of the lens is arranged on the light emergent path of the light source, one surface of the lens, which is far away from the light source, comprises a first free-form surface, and the first free-form surface is used for correcting and projecting the light to the free-form surface reflecting mirror; the free-form surface reflector is arranged on one side of the lens far away from the light source, and one surface of the free-form surface reflector facing the lens comprises a second free-form surface, and the second free-form surface is used for reflecting light rays to the liquid crystal screen. The light emitted by the light source is corrected by the lens, and the light and uniform light spots are finally obtained on the liquid crystal screen through the collimation effect of the free-form surface reflector.
Description
Technical Field
The present invention relates to the field of projection display technology, and in particular, to a backlight module for a light engine and a projector.
Background
The backlight system of the existing projector mainly comprises a light source, a reflecting cup, a Fresnel lens and an optical system consisting of a liquid crystal screen. The light source is arranged at the bottom of the reflecting plate, the Fresnel lens covers the top of the reflecting cup, and the liquid crystal screen is arranged above the Fresnel lens. The light emitted by the light source firstly acts on the Fresnel lens through the reflection of the reflecting cup, and then the light is projected onto the liquid crystal screen through the Fresnel lens. Although the light system has higher light utilization rate, the illumination uniformity after projection is general, and meanwhile, a smaller light angle is difficult to obtain, so that the picture quality of the final projection image is lower.
Disclosure of Invention
Based on the above, the invention aims to overcome the defects of the prior art, and provides a backlight module for an optical machine and a projector, wherein light rays emitted by a light source are corrected by a lens, and finally collimated light rays and uniform light spots are obtained on a liquid crystal screen through the collimation effect of a free-form surface reflector.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
a backlight module for a light machine and a projector comprises a light source, a lens, a free-form surface reflector and a liquid crystal screen; the light source is used for outputting light along the direction of the optical axis of the light source, the light incident surface of the lens is arranged on the light emergent path of the light source, one surface of the lens, which is far away from the light source, comprises a first free-form surface, and the first free-form surface is used for correcting and projecting the light to the free-form surface reflecting mirror; the free-form surface reflector is arranged on one side of the lens far away from the light source, and one surface of the free-form surface reflector facing the lens comprises a second free-form surface, and the second free-form surface is used for reflecting light rays to the liquid crystal screen.
As one embodiment, a distance between the light emitting surface of the light source and the vertex of the first free-form surface of the lens is a, a distance between the vertex of the first free-form surface of the lens and the vertex of the second free-form surface of the free-form surface mirror is b, a distance between the vertex of the second free-form surface of the free-form surface mirror and the liquid crystal screen is c, and a range of b is: a is less than or equal to b is less than or equal to 50a, and the range of c is as follows: c is more than or equal to 0.2b and less than or equal to 10b.
As one embodiment, the a is in the range of 5-50mm.
In one embodiment, the second free-form surface is a concave surface, the radius of curvature of the second free-form surface is R, and the range of R is 0.1 b.ltoreq.R.ltoreq.40b.
As one embodiment, the analytical formula of the second free-form surface is:
wherein c=1/R, C x Is the radius of curvature of the vertex of the second free-form surface in the X direction, C y Is the radius of curvature, k, of the vertex of the second free-form surface in the Y direction x Is the conical coefficient k in the X direction of the second free-form surface y Is the conical coefficient of the second free-form surface in the Y direction, A 2n 、B 2n Is the correction coefficient of the second free-form surface.
As an embodiment, when k is x ＝k y =0 and C x ＝C y And when the second free-form surface is a spherical surface.
As one embodiment, the center of the light source and the center of the lens are positioned on the same optical axis, and the included angle between the light source and the lens and the horizontal plane is alpha, and the angle range of alpha is 30 degrees less than or equal to alpha less than or equal to 90 degrees.
As one embodiment, the angle between the free-form surface reflecting mirror and the horizontal plane is beta, and the angle range of beta is 0.5α -15 degrees < beta < 0.5α+15 degrees.
As one embodiment, the second free-form surface is a convex surface, and the surface of the lens facing the light source is a flat surface or a concave surface.
As one embodiment, when the surface of the lens facing the light source is a plane, the light source is spaced apart from the lens; when the surface of the lens facing the light source is a concave surface, the light source is arranged in the concave surface.
Compared with the prior art, the backlight module for the optical machine and the projector has the beneficial effects that:
according to the invention, through structural improvement of the lens and the free-form surface reflector, after the light rays emitted by the light source are corrected by the lens, the collimation effect of the free-form surface reflector is adopted, so that the collimation degree and uniformity of the light rays reflected to the liquid crystal screen are better on the basis of ensuring the light utilization rate of the light rays emitted by the light source, and the picture quality of the final projection image is higher.
For a better understanding and implementation, the present invention is described in detail below with reference to the drawings.
Drawings
FIG. 1 is an optical block diagram of a prior art backlight system;
FIG. 2 is a schematic diagram of a backlight module for a light engine and a projector according to the present invention;
FIG. 3 is a second schematic diagram of a backlight module for a light engine and a projector according to the present invention;
FIG. 4 is a schematic diagram of a lens structure of a backlight module for a light engine and a projector according to the present invention;
FIG. 5 is a schematic diagram showing a structure between a light source and a lens of a backlight module for a light engine and a projector according to the present invention;
FIG. 6 is a second schematic diagram of the structure between the light source and the lens of the backlight module for the optical machine and the projector according to the present invention;
FIG. 7 is a schematic diagram of a free-form lens for a backlight module of an optical engine and a projector according to the present invention;
FIG. 8 is a schematic diagram of a free-form lens structure of a backlight module for a light engine and a projector according to the second embodiment of the invention.
Reference numerals illustrate: 10. a light source; 20. a lens; 21. a first free-form surface; 30. a free-form surface lens; 31. a second free-form surface; 40. a liquid crystal screen.
Detailed Description
For further illustration of the various embodiments, the invention is provided with the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments and together with the description, serve to explain the principles of the embodiments. With reference to these matters, one of ordinary skill in the art will understand other possible implementations and advantages of the present invention.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "left", "right", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus are not to be construed as limiting the present invention.
As shown in fig. 1, an optical structure diagram of a backlight system of the prior art is shown. The existing backlight system mainly comprises a light source, a reflecting cup, a Fresnel lens and an optical system consisting of a liquid crystal display screen. The light source is arranged at the bottom of the reflecting plate, the Fresnel lens covers the top of the reflecting cup, and the liquid crystal display screen is arranged above the Fresnel lens. The light emitted by the light source firstly acts on the Fresnel lens through the reflection of the reflecting cup, and then the light is projected onto the liquid crystal display screen through the Fresnel lens. Although the light system has higher light utilization rate, the illumination uniformity after projection is general, and meanwhile, a smaller light angle is difficult to obtain, so that the picture quality of the final projection image is lower.
In the related art, the backlight module of the optical machine and the projector has three important technical index requirements: uniformity, collimation, and light utilization. Wherein, the uniformity is the ratio of the minimum illumination to the maximum illumination of the light irradiated on the receiving surface of the LCD screen; the collimation degree refers to an included angle between the light and the normal line of the plane where the liquid crystal screen is positioned, and the smaller the collimation degree is, the more parallel the whole light irradiated on the liquid crystal screen tends to be, and the smaller the light loss of the light passing through the liquid crystal screen and the projection lens is; the light utilization rate refers to the ratio of the energy finally emitted by the backlight module to the energy emitted by the light source.
Referring to fig. 2 to 8, the present embodiment provides a backlight module for a light engine and a projector, which includes a light source 10, a lens 20, a free-form surface reflector and a liquid crystal screen 40; the light source 10 is used for outputting light along the direction of the optical axis of the light source 10, the light incident surface of the lens 20 is arranged on the light emergent path of the light source 10, one surface of the lens 20, which is far away from the light source 10, comprises a first free-form surface 21, and the first free-form surface 21 is used for correcting and projecting the light to the free-form surface reflector; the free-form surface reflector is disposed on a side of the lens 20 away from the light source 10, and a surface of the free-form surface reflector facing the lens 20 includes a second free-form surface 31, and the second free-form surface 31 is used for reflecting light to the liquid crystal screen 40.
Therefore, in the backlight module of this embodiment, through the structural improvement of the lens 20 and the free-form surface reflector, after the light emitted by the light source 10 is corrected by the lens 20, the collimation effect of the free-form surface reflector is adopted, so that the collimation degree and uniformity of the light emitted from the light source 10 are better on the basis of ensuring the light utilization rate, and the picture quality of the final projection image is higher.
Specifically, the center of the light source 10 and the center of the lens 20 of the present embodiment are located on the same optical axis, and the angle α between the light source 10 and the lens 20 and the horizontal plane is in the range of 30 ° +.ltoreq.90 °. Further, the angle between the free-form surface reflecting mirror and the horizontal plane is beta, and the angle range of beta is 0.5α -15 degrees < beta < 0.5α+15 degrees. Among them, the value of β in this embodiment is preferably 0.5α.
Alternatively, the distance between the light emitting surface of the light source 10 and the vertex of the first free-form surface 21 of the lens 20 is a, the distance between the vertex of the first free-form surface 21 of the lens 20 and the vertex of the second free-form surface 31 of the free-form surface mirror is b, and the distance between the vertex of the second free-form surface 31 of the free-form surface mirror and the liquid crystal screen 40 is c. Wherein, the range of a of the embodiment is 5-50mm, and the range of b is: the range of a is more than or equal to b and less than or equal to 50a, and c is as follows: c is more than or equal to 0.2b and less than or equal to 10b.
In the present embodiment, the second free-form surface 31 of the free-form surface mirror has a concave shape, and the radius of curvature of the second free-form surface 31 is R, and R is in the range of 0.1 b.ltoreq.R.ltoreq.40 b. In addition, the analytical formula of the second free-form surface 31 in this embodiment is:
wherein c=1/R, C x In the X direction of the vertex of the second free-form surface 31Radius of curvature, C y Radius of curvature, k, in the Y-direction of the vertex of the second free-form surface 31 x Is the conic coefficient, k, of the second free-form surface 31X direction y Is the conical coefficient of the second free-form surface 31Y direction, A 2n 、B 2n Is the correction coefficient for the second free-form surface 31.
When said k is x ＝k y =0 and C x ＝C y In this case, the second free-form surface 31 is a spherical surface.
Further, the resolution of the first free-form surface 21 of the lens 20 of the present embodiment is also the resolution of the second free-form surface 31, which is not repeated in this embodiment. The first free-form surface 21 and the second free-form surface 31 of the present embodiment include a curved surface, a deformed aspherical surface, a spherical surface, and the like formed by zernike polynomials.
Alternatively, the second free-form surface 31 of the present embodiment is convex. In addition, the surface of the lens 20 facing the light source 10 in this embodiment is a flat surface or a concave surface. As shown in fig. 5, when the surface of the lens 20 facing the light source 10 is a plane, the light source 10 is disposed at a distance from the lens 20; as shown in fig. 6, when the surface of the lens 20 facing the light source 10 is concave, the light source 10 is disposed in the concave.
In addition, when the surface of the lens 20 facing the light source 10 in the present embodiment is a concave surface, the concave surface of the lens 20 may be a free-form surface structure, and the resolution of the free-form surface structure is also the resolution of the second free-form surface 31, which is not repeated in the present embodiment.
The light source 10 of the present embodiment may be one of a COB light source 10, an integrated LED light source 10, a point light source 10, a surface light source 10, a laser light source 10, a mercury lamp, and the like; the lens 20 of this embodiment may be made of plastic materials such as PMMA and PC, or glass materials such as borosilicate glass, quartz glass, H-K9 and H-K51; the free-form surface reflecting mirror of the embodiment can be made of plastic materials such as PMMA, PC and the like, glass materials such as high borosilicate glass, quartz glass, H-K9, H-K51 and the like, and metal materials such as aluminum alloy, stainless steel and the like.
The above examples only show a few embodiments of the present invention, which are described in more detail and detail, but the scope of the backlight module for the optical engine and the projector is not limited by the above examples. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention.
Claims (10)
1. A backlight module for a light engine and a projector, comprising:
a light source, a lens, a free-form surface reflector and a liquid crystal screen;
the light source is used for outputting light along the direction of the optical axis of the light source, the light incident surface of the lens is arranged on the light emergent path of the light source, one surface of the lens, which is far away from the light source, comprises a first free-form surface, and the first free-form surface is used for correcting and projecting the light to the free-form surface reflecting mirror; the free-form surface reflector is arranged on one side of the lens far away from the light source, and one surface of the free-form surface reflector facing the lens comprises a second free-form surface, and the second free-form surface is used for reflecting light rays to the liquid crystal screen.
2. The backlight module for a light engine and a projector according to claim 1, wherein:
the distance between the light emitting surface of the light source and the vertex of the first free-form surface of the lens is a, the distance between the vertex of the first free-form surface of the lens and the vertex of the second free-form surface of the free-form surface reflecting mirror is b, the distance between the vertex of the second free-form surface of the free-form surface reflecting mirror and the liquid crystal screen is c, and the range of b is as follows: a is less than or equal to b is less than or equal to 50a, and the range of c is as follows: c is more than or equal to 0.2b and less than or equal to 10b.
3. The backlight module for a light engine and a projector according to claim 2, wherein:
the range of a is 5-50mm.
4. The backlight module for a light engine and a projector according to claim 2, wherein:
the second free-form surface is a concave surface, the curvature radius of the second free-form surface is R, and the range of R is more than or equal to 0.1b and less than or equal to 40b.
5. The backlight module for a light engine and a projector according to claim 4, wherein:
the analytical formula of the second free-form surface is as follows:
wherein c=1/R, C x Is the radius of curvature of the vertex of the second free-form surface in the X direction, C y Is the radius of curvature, k, of the vertex of the second free-form surface in the Y direction x Is the conical coefficient k in the X direction of the second free-form surface y Is the conical coefficient of the second free-form surface in the Y direction, A 2n 、B 2n Is the correction coefficient of the second free-form surface.
6. The backlight module for a light engine and a projector according to claim 5, wherein:
when said k is x ＝k y =0 and C x ＝C y And when the second free-form surface is a spherical surface.
7. The backlight module for a light engine and a projector according to claim 1, wherein:
the center of the light source and the center of the lens are positioned on the same optical axis, the included angle between the light source and the lens and the horizontal plane is alpha, and the angle range of alpha is more than or equal to 30 degrees and less than or equal to 90 degrees.
8. The backlight module for a light engine and a projector according to claim 7, wherein:
the included angle between the free-form surface reflecting mirror and the horizontal plane is beta, and the angle range of beta is 0.5alpha-15 degrees and less than beta is less than 0.5alpha+15 degrees.
9. The backlight module for a light engine and a projector according to claim 1, wherein:
the second free curved surface is a convex surface, and the surface of the lens facing the light source is a plane or a concave surface.
10. The backlight module for a light engine and a projector according to claim 9, wherein:
when the surface of the lens facing the light source is a plane, the light source and the lens are arranged at intervals; when the surface of the lens facing the light source is a concave surface, the light source is arranged in the concave surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310512369.XA CN116520628A (en) | 2023-05-08 | 2023-05-08 | Backlight module for optical machine and projector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310512369.XA CN116520628A (en) | 2023-05-08 | 2023-05-08 | Backlight module for optical machine and projector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116520628A true CN116520628A (en) | 2023-08-01 |
Family
ID=87395670
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310512369.XA Pending CN116520628A (en) | 2023-05-08 | 2023-05-08 | Backlight module for optical machine and projector |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116520628A (en) |
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2023
- 2023-05-08 CN CN202310512369.XA patent/CN116520628A/en active Pending
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