CN103885156A - Projection lenses and projection device - Google Patents
Projection lenses and projection device Download PDFInfo
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- CN103885156A CN103885156A CN201410058474.1A CN201410058474A CN103885156A CN 103885156 A CN103885156 A CN 103885156A CN 201410058474 A CN201410058474 A CN 201410058474A CN 103885156 A CN103885156 A CN 103885156A
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Abstract
The invention discloses projection lenses and a projection device. The projection lenses comprise a first group of lenses and a second group of lenses. The first group of lenses has negative diopter and is in the proximity to the object side. The first group of the lenses has a first lens having the negative diopter. The first lens comprises a first surface and a second surface which are opposite. The first surface faces the object side and the curvature radius of the first surface is greater or equal to 500 millimeters. The lens group has positive diopter and is adjacent to the image side. The second lens group comprises a third surface facing the object side. The effective focus of the projection lens is f, the distance between the second surface and the third surface is d, the quantity of the projection lenses is n and d/f>=1.6, 7>=n>=4.
Description
Technical field
The invention provides a kind of projection lens and projection arrangement, espespecially a kind of projection lens and dependent projections device that can effectively prevent light leak and ghost.
Background technology
Common projector is in order to improve image vividness on the market, and its display comparison degree does higher and higher, and thing followed shortcoming is that projection lens easily produces light leak and ghost on screen.Refer to Fig. 4, the part-structure schematic diagram of the projection arrangement 50 that Fig. 4 is prior art.Projection arrangement 50 comprises image-generating unit 42 and projection lens 40.Image-generating unit 42 provides the light of tool image to be projected to screen by projection lens 40.Projection lens 40 comprises the second lens combination 46 that has negative dioptric first lens group 44 and have positive diopter.First lens group 44 is near thing side (screen), and the second lens combination 46 is near picture side (image-generating unit 42).First lens group 44 at least comprises one and has negative dioptric meniscus lens 48.Meniscus lens 48 has relative first surface s1 and second surface s2, and the radius-of-curvature of first surface s1 and second surface s2 is about 100～200mm.Two surperficial s1 of meniscus lens 48, s2 is cambered surface, the incident angle that light enters meniscus lens 48 approaches the normal vector of first surface s1, and light is easily reflected back the second lens combination 46 and image-generating unit 42 (for example digital micro-mirror or liquid crystal panel) along incident path by first surface s1.In the time that light enters first lens group 44 from the second lens combination 46, light can produce the ring of light and hot spot by multiple reflections between first lens group 44 and the second lens combination 46, and meaning is commonly referred to as the defect of ghost.Refer to Fig. 5, the projection lens 40 that Fig. 5 is prior art is incident upon the effect schematic diagram of screen.On screen, can form with the ghost (in digital optical projector) of image-generating unit profile or occur unexpected property brightness (in liquid crystal projector) in some region.Position, the shape of ghost are indefinite, destroy image composition and attractive in appearance, therefore how to design a kind of projection lens that prevents ghost, are just the target of giving priority to of related optical industry.
Summary of the invention
The invention provides a kind of projection lens and the projection arrangement that can effectively avoid producing light leak and ghost, to solve the above problems.
The invention provides a kind of projection lens, it includes first lens group and the second lens combination.First lens group has negative diopter and contiguous thing side.First lens group comprises and has negative dioptric first lens.First lens comprises relative first surface and second surface.First surface is towards thing side, and the radius-of-curvature of first surface is more than or equal to 500 millimeters.The second lens combination has positive diopter and contiguous as side.The second lens combination comprises the 3rd surface towards thing side.The effective focal length of projection lens is f, and the distance on second surface and the 3rd surface is d, and the lens total quantity of projection lens is n, and d/f >=1.6,7 >=n >=4.
Preferably, in described projection lens, the focal length of this first lens group is f1, and 1.5≤f1/f≤3.5.
Preferably, in described projection lens, the radius-of-curvature of this first surface is infinitely great, and this first lens is plano-concave lens.
Preferably, in described projection lens, this first lens group separately comprises at least one the second lens, and these at least one second lens are placed between this first lens and this second lens combination.
Preferably, in described projection lens, this projection lens is non-telecentric system.
The present invention also provides a kind of projection arrangement, and this projection arrangement is used for projecting image to screen.Projection arrangement includes light source, image-generating unit and projection lens.Light source and image-generating unit are respectively in order to provide and to receive light.Projection lens is arranged between image-generating unit and screen, arrives screen in order to throw light.Projection lens comprises first lens group and the second lens combination.First lens group has negative diopter and contiguous thing side.First lens group comprises and has negative dioptric first lens.First lens comprises relative first surface and second surface.First surface is towards thing side, and the radius-of-curvature of first surface is more than or equal to 500 millimeters.The second lens combination has positive diopter and contiguous as side.The second lens combination comprises the 3rd surface towards thing side.The effective focal length of projection lens is f, and the distance on second surface and the 3rd surface is d, and the lens total quantity of projection lens is n, and d/f >=1.6,7 >=n >=4.
Preferably, in described projection arrangement, the focal length of this first lens group is f1, and 1.5≤f1/f≤3.5.
Preferably, in described projection arrangement, the radius-of-curvature of this first surface is infinitely great, and this first lens is plano-concave lens.
Preferably, in described projection arrangement, this first lens group separately comprises at least one the second lens, and these at least one second lens are placed between this first lens and this second lens combination.
Preferably, in described projection arrangement, it separately comprises filter unit and reflecting element.Filter unit receives this light of this light source and this light is filtered as polychromatic light; Reflecting element is in order to reflect this polychromatic light; Wherein, this image-generating unit receives through this polychromatic light of this reflecting element and is passed to this projection lens to project this screen.
Compared with prior art, the present invention first lens group the thing side position of close screen plano-concave lens is set.The first surface of plano-concave lens is towards thing side.First surface can be flat surface or micro-almost plane with arc, as long as the radius-of-curvature of first surface is not less than 500 millimeters, the first lens of plano-concave shape just can be by the light from the second lens combination along the direction dissipation that is different from former input path, avoid light reflection to get back to image-generating unit, prevent from occurring on screen unexpected image (as ghost) or brightness.Compare prior art, projection lens of the present invention and dependent projections device can be applicable to the optical system that lens numbers is few and lens combination spacing is large, reach the object of screen without ghost.
Brief description of the drawings
Fig. 1 is the schematic diagram of the projection arrangement of one embodiment of the invention;
Fig. 2 is the part-structure schematic diagram of the projection arrangement of one embodiment of the invention;
Fig. 3 is the light path schematic diagram of the projection lens of another embodiment of the present invention;
Fig. 4 is the part-structure schematic diagram of the projection arrangement of prior art;
Fig. 5 is that the projection lens projects of prior art is at the effect schematic diagram of screen.
Embodiment
For making that object of the present invention, structure, feature and function thereof are had to further understanding, hereby coordinate embodiment to be described in detail as follows.
Refer to Fig. 1, the schematic diagram of the projection arrangement 10 that Fig. 1 is one embodiment of the invention.Projection arrangement 10 is used for projecting image to screen 12.Projection arrangement 10 comprises light source 14, image-generating unit 16, projection lens 18, filter unit 20 and reflecting element 22.Light source 14 is exported light, and filter unit 20 receives light and light is filtered into multiple coloured light, is reflected element 22 reflects and received by image-generating unit 16 through filter unit 20 light after treatment.Image-generating unit 16 receives from multiple coloured light of reflecting element 22 and is delivered to projection lens 18.Projection lens 18 is arranged between image-generating unit 16 and screen 12, in order to by the ray cast from image-generating unit 16 to screen 12.In digit optical processing (DLPTM) projector, filter unit 20 is colour wheel, and image-generating unit 16 is digital minitype reflector (Digital Micromirror Device, DMD), and reflecting element 22 is concave mirror.In liquid crystal projector, filter unit 20 is optical filters, and reflecting element 22 is mirror surfaces, and image-generating unit 16 is liquid crystal panels.
Refer to Fig. 2, the part-structure schematic diagram of the projection arrangement 10 that Fig. 2 is one embodiment of the invention.Projection lens 18 comprises first lens group 24 and the second lens combination 26.First lens group 24 contiguous screens 12 (being thing side), the second lens combination 26 contiguous image-generating units 16 (as side).First lens group 24 has negative diopter and in order to divergent rays.The second lens combination 26 has positive diopter and in order to polymerization light.First lens group 24 comprises and has negative dioptric first lens 28.First lens 28 comprises relative first surface S1 and second surface S2, respectively towards screen 12 and the second lens combination 26.First surface S1 is preferably plane, and its radius-of-curvature is infinitely great, and first lens 28 is plano-concave lens; Or first surface S1 can be the unconspicuous plane of radian, its radius-of-curvature is more than or equal to 500 millimeters, and now first lens 28 is the lens of approximate plano-concave.
The another alternative of first lens group 24 comprises at least one second lens 30, is arranged between first lens 28 and the second lens combination 26, and first lens 28 is arranged on the left side of first lens group 24, as shown in Figure 2.The second lens 30 can have positive diopter or negative diopter, depending on design requirement.No matter first lens group 24 separately comprises one or more the second lens 30, and first lens 28 is all arranged on the position of the most close screen 12.First lens 28 of the present invention (plano-concave lens) is positioned at the outermost of first lens group 24, be delivered to the incident light of first surface S1 in order to dissipation the second lens combination 26, effectively avoid first lens 28 to be reflected back the second lens combination 26 and to cause ghost following original optical path from the incident light of the second lens combination 26.
Refer to Fig. 3, the light path schematic diagram of the projection lens 18 that Fig. 3 is another embodiment of the present invention.The projection lens 18 of the present embodiment omits the second lens 30, and the element that other and previous embodiment have identical numbering has same structure and function, so no longer repeat specification.The light of light source 14 is delivered to after image-generating unit 16 via filter unit 20 and reflecting element 22, and light can enter by the second lens combination 26 first lens 28 of first lens group 24.Because the first surface S1 of first lens 28 is plane or almost plane, can strengthen the incident angle of light incident first surface S1, make reflection ray not can along incident path be reflected back the second lens combination 26 and image-generating unit 16, even if reflection ray is away from projection lens 18.Compared to the projection lens 40 of prior art, first lens 28 of the present invention (plano-concave lens) can avoid light reflection to return projection lens 18.It should be noted that at digit optical processing (DLP
tM) in projector, light can not shine along input path reflection the image-generating unit 16 (for example DMD) of closed condition (Off mode), avoids producing as the ghost of hot spot or the ring of light; In liquid crystal projector, light can not shine image-generating unit 16 (for example liquid crystal panel) along input path reflection, avoids region to occur unexpected brightness.
The lens numbers of conventional lenses less or two lens combination spacing larger, more easily produce ghost.It is worth mentioning that, projection lens 18 of the present invention is the in the situation that of a small amount of lens, the characteristic that the first surface S1 that utilizes first lens 28 is plane (or almost plane) reduces the amount of light that is reflected back the second lens combination 26 from first lens group 24, can obtain the effect of better elimination ghost/light leak.For instance, the lens total quantity of projection lens 18 is n, and 7 >=n >=4.In addition, the second lens combination 26 of the present invention comprises the 3rd surperficial S3 towards screen 12, and the effective focal length of projection lens 18 is f, and the distance of second surface S2 and the 3rd surperficial S3 is d, and d/f >=1.6.Projection lens 18 of the present invention also can be obtained the effect of better elimination ghost/light leak in first lens group 24 and the second lens combination 26 situation relatively far apart.
Table 1 has been enumerated the better parameter value of each spherical lens of projection lens 18.In table 1, the value of " distance " represents that the surface of corresponding these row is to the surperficial spacing of next column, the i.e. spacing of this row minute surface and next column minute surface.In embodiments of the present invention, the distance d of second surface S2 and the 3rd surperficial S3 is 37.17013mm, and the effective focal length f of projection lens 18 is 21.9mm, meets the condition of aforementioned d/f >=1.6.Wherein, lens parameter of the present invention can be not limited to shown in table 1, depending on design requirement, is illustrated so no longer other is implemented to aspect.
Table 1
Moreover, the projection lens 18 of the non-telecentric system of the better use of the present invention, wherein the focal length of first lens group 24 is f1, and meets the condition of 1.5≤f1/f≤3.5.The entrance pupil positional distance image-generating unit 16 of the exit pupil position of the light source 14 of non-telecentric system and projection lens 18 has segment distance, therefore do not need by field lens or the completely reflecting mirror light path of transferring, the optical element quantity that can effectively reduce projection arrangement 10 reduces cost of products.Table 2 is pointed out better focal length value of the present invention, and for example effective focal length f of projection lens 18 is 21.9mm, and the focal distance f 1 of first lens group 24 is-51.29mm.If the ratio of f1/f is lower than lower limit, f1 is less, and the refractive power of first lens group 24 is stronger, easily produces aberration.In addition, hour, the lens numbers of projection lens 18 is more for the ratio of f1/f, and light is difficult to get back to image-generating unit 16 along input path through the refraction of multi-disc lens, is not suitable for first lens 28 that the present invention utilizes plano-concave and solves the enforcement aspect of light leak/ghost.If the ratio of f1/f is higher than the upper limit, f1 is larger, and the refractive power of first lens group 24 is more weak, and the enlargement ratio of projection lens 18 is low, does not meet consumer demand.
| f(mm) | f1(mm) |
| 21.9 | -51.290947 |
Table 2
One end of conventional lenses the most contiguous thing side in lens combination arranges the meniscus lens of two sides convex-concave, and it can form the ghost (in digital optical projector) with image-generating unit 16 external form profiles on screen 12.The first lens of two sides plano-concave or approximate plano-concave is arranged on first lens group 24 outermost by the present invention, can effectively reach the object of eliminating ghost.Projection lens 18 do not see completely at the image of screen 12 tool image-generating unit 16 external form profile ghost or there is unexpected brightness.
The second lens combination 26 alternatives comprise multiple lens, for example the 3rd lens 32, the 4th lens 34, the 5th lens 36 and the 6th lens 38, as shown in Figure 3.The 3rd lens 32, the 4th lens 34 and the 6th lens 38 have positive diopter; The 5th lens 36 have negative diopter.The lens numbers of right the second lens combination 26 and ametropia characteristic thereof can be not limited to described in this embodiment, depending on design requirement, all invention categories that provides the lens combination of polymerization light function all to belong to the second lens combination 26, no longer illustrate other embodiment with identical or close light path characteristic in detail in this.
Comprehensive, the present invention first lens group the thing side position of close screen plano-concave lens is set.The first surface of plano-concave lens is towards thing side.First surface can be flat surface or micro-almost plane with arc, as long as the radius-of-curvature of first surface is not less than 500 millimeters, the first lens of plano-concave shape just can be by the light from the second lens combination along the direction dissipation that is different from former input path, avoid light reflection to get back to the image-generating unit of closed condition, prevent from occurring on screen unexpected image (as ghost).Compare prior art, projection lens of the present invention and dependent projections device can be applicable to the optical system that lens numbers is few and lens combination spacing is large, reach the object of screen without ghost.
The foregoing is only preferred embodiment of the present invention, all equalizations of doing according to the present patent application the scope of the claims change and modify, and all should belong to covering scope of the present invention.
Claims (10)
1. a projection lens, is characterized in that, it includes:
First lens group, have negative diopter and contiguous thing side, this first lens group comprises and has negative dioptric first lens, and this first lens comprises relative first surface and a second surface, this first surface is towards this thing side, and the radius-of-curvature of this first surface is more than or equal to 500 millimeters; And
The second lens combination, has positive diopter and contiguous as side, and this second lens combination comprises the 3rd surface towards this thing side;
Wherein, the effective focal length of this projection lens is f, and the distance on this second surface and the 3rd surface is d, and the lens total quantity of this projection lens is n, and d/f >=1.6,7 >=n >=4.
2. projection lens as claimed in claim 1, is characterized in that, the focal length of this first lens group is f1, and 1.5≤f1/f≤3.5.
3. projection lens as claimed in claim 1, is characterized in that, the radius-of-curvature of this first surface is infinitely great, and this first lens is plano-concave lens.
4. projection lens as claimed in claim 1, is characterized in that, this first lens group separately comprises at least one the second lens, and these at least one second lens are placed between this first lens and this second lens combination.
5. projection lens as claimed in claim 1, is characterized in that, this projection lens is non-telecentric system.
6. a projection arrangement, is used for projecting image to screen, it is characterized in that, this projection arrangement includes: light source, provides light;
Image-generating unit, receives this light; And
Projection lens, is arranged between this image-generating unit and this screen, and in order to project this light to this screen, this projection lens comprises:
First lens group, have negative diopter and contiguous this screen, this first lens group comprises and has negative dioptric first lens, and this first lens comprises relative first surface and a second surface, this first surface is towards this screen, and the radius-of-curvature of this first surface is more than or equal to 500 millimeters; And
The second lens combination, has positive diopter and contiguous this image-generating unit, and this second lens combination comprises the 3rd surface towards this screen;
Wherein, the effective focal length of this projection lens is f, and the distance on this second surface and the 3rd surface is d, and the lens total quantity of this projection lens is n, and d/f >=1.6,7 >=n >=4.
7. projection arrangement as claimed in claim 6, is characterized in that, the focal length of this first lens group is f1, and 1.5≤f1/f≤3.5.
8. projection arrangement as claimed in claim 6, is characterized in that, the radius-of-curvature of this first surface is infinitely great, and this first lens is plano-concave lens.
9. projection arrangement as claimed in claim 6, is characterized in that, this first lens group separately comprises at least one the second lens, and these at least one second lens are placed between this first lens and this second lens combination.
10. projection arrangement as claimed in claim 6, is characterized in that, it separately comprises:
Filter unit, receives this light of this light source and this light is filtered as polychromatic light; And
Reflecting element, in order to reflect this polychromatic light;
Wherein, this image-generating unit receives through this polychromatic light of this reflecting element and is passed to this projection lens to project this screen.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410058474.1A CN103885156A (en) | 2014-02-21 | 2014-02-21 | Projection lenses and projection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410058474.1A CN103885156A (en) | 2014-02-21 | 2014-02-21 | Projection lenses and projection device |
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| CN103885156A true CN103885156A (en) | 2014-06-25 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201410058474.1A Pending CN103885156A (en) | 2014-02-21 | 2014-02-21 | Projection lenses and projection device |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1768289A (en) * | 2003-03-28 | 2006-05-03 | 3M创新有限公司 | Low element count projection lenses for use with pixelized panels |
| US20100053774A1 (en) * | 2008-09-01 | 2010-03-04 | Tomoyuki Baba | Small projection lens and projection display device using the same |
| US20110026131A1 (en) * | 2009-07-31 | 2011-02-03 | Canon Kabushiki Kaisha | Zoom lens and optical apparatus including the same |
| US20110115946A1 (en) * | 2009-11-16 | 2011-05-19 | Canon Kabushiki Kaisha | Zoom lens and image pickup apparatus including the same |
| CN102608735A (en) * | 2011-01-19 | 2012-07-25 | 佛山普立华科技有限公司 | Zooming projection lens |
-
2014
- 2014-02-21 CN CN201410058474.1A patent/CN103885156A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1768289A (en) * | 2003-03-28 | 2006-05-03 | 3M创新有限公司 | Low element count projection lenses for use with pixelized panels |
| US20100053774A1 (en) * | 2008-09-01 | 2010-03-04 | Tomoyuki Baba | Small projection lens and projection display device using the same |
| US20110026131A1 (en) * | 2009-07-31 | 2011-02-03 | Canon Kabushiki Kaisha | Zoom lens and optical apparatus including the same |
| US20110115946A1 (en) * | 2009-11-16 | 2011-05-19 | Canon Kabushiki Kaisha | Zoom lens and image pickup apparatus including the same |
| CN102608735A (en) * | 2011-01-19 | 2012-07-25 | 佛山普立华科技有限公司 | Zooming projection lens |
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Application publication date: 20140625 |