The optical system and the LCD projecting system of a kind of colour deciliter
Technical field
The present invention relates to the optical system of a kind of colour deciliter, particularly utilize the LCD projecting system of colored deciliter optical system.
Background technology
Development along with LCOS, opaque projector has had that processing procedure is simple, cost is low and the resolution advantages of higher, but its light engine difficult design, and still have subproblem to wait to overcome on the contrast, the key part and component of liquid crystal projector has light-source system, display module, dividing-mixing optical system, electronic circuit system etc., and wherein dividing-mixing optical system is the principal element of reaction projection image effect.
As Fig. 1 is in order to the light path principle figure of known beam splitting system to be described, this light path system closes Amici prism with 4 groups of polarizations and the reflective nematic liquid crystal panel of Red is formed, and adopts coaxial light path design.As shown in Figure 1, this beam splitting system 10 comprises that 4 groups of polarizations close 11,12,13 and 14,4 groups of polarization phase delayers of Amici prism (polarizer retarder), 15,16,17 and 18, three dichroic liquid crystal panels 20,21 and 22 and one polaroid 19.Wherein, each polarization closes Amici prism and all contains two fens prisms, that is, polarization close Amici prism 11 comprise branch prism 111 and 112, polarization close Amici prism 12 comprise branch prism 121 and 122, polarization close Amici prism 13 comprise branch prism 131 and 132 and polarization close Amici prism 14 and comprise branch prism 141 and 142.
The light source 1 of beam splitting system 10 can produce a polar biased light beam 2 that is in the S polarization state, polar biased light beam 2 is subjected to the reflection of three dichroic liquid crystal panels 20,21 and 22 in beam splitting system 10, this three liquid crystal panel is then accepted signal of video signal to be throwed, so, leave the beam splitting system light beam and promptly project this signal representative image to be throwed according to this.
Polarization phase delayer 15,16,17 and 18 can be adjusted the polarization state of particular color of light bundle, wherein, polarization phase delayer 15 and 18 can make by red constant with the blue light beam polarization state therebetween, and make by green beam polarization state therebetween and convert the P attitude to from the S attitude, polarization phase delayer 16 and 17 then can make by the blue light beam polarization state is constant therebetween, and makes by red beam polarization state therebetween and convert the P attitude to from the S attitude.
As shown in Figure 1,, be in the red blue light components 2a of S attitude and can be reflected in the polarization phase delayer 16 when light beam 2 arrives when dividing prisms 111 and 112 interfaces, be in P attitude green component 2b then transmission divide prism 112 and enter polarization and close in the Amici prism 12.
Light component 2b is by dividing prism 121 and 122 interfaces, then converted to S attitude blue beam 3b by the P attitude by 20 reflections of green liquid crystal panel, blue beam 3b continues to enter polarization and closes in the Amici prism 14, and quilt divides prism 141 and the reflection of 142 interfaces and continues to pass through phase delay device 18, so can convert the P attitude to by the S attitude by blue beam 3b therebetween, last also by P attitude polaroid 19, and form projection image green component 4b.
In like manner, polarization phase delayer 16 can make by red blue light components 2a therebetween can be divided into keep S polarization state 21a, with convert P attitude red beam 21b to from the S attitude.Wherein, red beam 21b passes branch prism 131 and 132 interfaces, and be subjected to red liquid crystal panel 22 reflection and be converted to S attitude red beam 22b, and then by polarization phase delayer 17, so will convert the P attitude to by the S attitude by red beam 22b therebetween, and then transmit polarization and close Amici prism 14, polarization phase delayer 18, and polaroid 19, and form projection image blue light components 23a.So far, be in P attitude light component 23b, 23a and the superimposed LCD projector image that promptly becomes of 4b with above red bluish-green three strands.
Yet the problem that exists in the above-mentioned known technology is:
1. the dirigibility of light path design is restricted.The polarization that prior art is utilized deciliter light prism, when light beam can not be at an angle (or at least will cone angle in) at principal angle of incidence be incident on the polarization deciliter light prism, this polarization deciliter light prism just can not normal operation.This is that the single incident angle that is necessary for 45 ° designs because usually in polarization deciliter light prism cube, if depart from 2 ° of such little incident angles even light departs from this angle, it is relatively poor that its performance all can become.Thereby the dirigibility of light path design is restricted.
2. the big and Heavy Weight of size.Conventional art requires to use polarization deciliter light prism cube.This cube is imposed on system with some requirement and loss.The requirement of being forced comprises that needs solve the thermal force of this big sheet glass, and need not have the high-quality material of stress birefrin etc., when will increase its cost, also needs to increase some cooling settings, thereby further increases its volume and weight.
3. poor stability.Modern light source produces very high thermal gradient immediately in polarization deciliter light prism after connecting light.Can cause thermally induced birefringence at the most, and thermally induced birefringence can cause between the polarization string around.And the long-time irradiation of high light causes some material to change character (flavescence by photooxidation usually).Therefore, the long-time radiation that needs polarization deciliter light prism can bear high temperature and light source.
4. resolution and poor contrast.Require the image display system of the property of transmission and reflectivity properties to have several key characters, for projection device, the high density information image that effectively is placed on light source on the screen and on screen, obtains high resolving power and contrast, all require the product of p-polarization transmission rate and s-polarized reflectance must be big, and the polarization color splitting and mixing prism cube of prior art can not satisfy as above requirement.
Summary of the invention
It is big to an object of the present invention is to provide a kind of conversion efficiency, accepts angular width, the LCD projecting system that size and weight high-lighting diminish.A kind of brightness height, the high and cheap image projection system of contrast.
The invention is characterized in that owing to adopt plate polarizer, the not only high temperature resistant strong illumination of this plate polarizer, to receive angular width, Heat stability is good, size little, these advantages enough satisfy characteristics such as compact light path design and high-contrast.
The object of the present invention is achieved like this: an optical system, that comprises three liquid crystal panel color splitting and mixings comprises the optical system and the crystal projection picture system thereof of two biliquid crystal panel color splitting and mixings.
Wherein this comprises that the optical system of three liquid crystal panel color splitting and mixings comprises one first color selector, one first plate polarizer, one second plate polarizer, one first liquid crystal panel, one second liquid crystal panel, one the 3rd liquid crystal panel, a phase delay device and a color-combination prism.
This first color selector wherein, by first color selector, and a p polarization second frequency band light and p polarization the 3rd frequency band light are by this first color selector reflection with a p polarization first frequency band light of the p polarized light of incident;
This first plate polarizer makes the above-mentioned p polarization first frequency band light by first plate polarizer;
This phase delay device makes the above-mentioned p polarization second frequency band light convert the s polarization second frequency band light to, and makes p polarization the 3rd frequency band light by this phase delay device;
This second plate polarizer makes the above-mentioned s polarization second frequency band light reflect by second plate polarizer, and makes p polarization the 3rd frequency band light by this second plate polarizer;
This first reflection type liquid crystal panel is reflected into the s polarization first frequency band optical image with the above-mentioned p polarization first frequency band light;
This second reflection type liquid crystal panel is reflected into the p polarization second frequency band optical image with the above-mentioned s polarization second frequency band light, and the above-mentioned p polarization second frequency band image is by second plate polarizer;
This three-mirror reflective liquid crystal panel converts above-mentioned p polarization the 3rd frequency band light to s polarization the 3rd frequency band optical image, and reflects by second plate polarizer;
This color-combination prism is accepted the above-mentioned s polarization first frequency band optical image, and p polarization second frequency band optical image and s polarization the 3rd frequency band optical image become LCD projector image;
Wherein also can comprise one second phase delay device between this second plate polarizer and this color-combination prism.Described second phase delay device makes the described p polarization second frequency band optical image convert the s polarization second frequency band optical image to, and wherein first plate polarizer and second plate polarizer have the disperse awl of useful of half-angle between about 10 ° to 25 °.
Present embodiment is in order further to increase contrast of the present invention, present embodiment also can be replaced into color-combination prism common polarization deciliter light prism, corresponding like this second phase delay device converts third phase position delayer to, wherein this third phase position delayer converts the ruddiness image r2 of above-mentioned s polarization to the ruddiness image r3 of p polarization, thereby the ruddiness image r3 of the p polarization of incident polarization deciliter light prism and the blue light image b3 of P polarization pass this polarization deciliter light prism, and s polarized green light image g2 enters imaging system by this polarization deciliter light prismatic reflection.
Of the present invention first comprises the optical system of two biliquid crystal panel color splitting and mixings, be fit to a p optical rotation and change s polarization color image into, it comprises: a color selector, one p polarization, the first frequency band light of above-mentioned P light beam is passed through this color selector, and a p polarization second frequency band light reflects away by this color selector;
This first plate polarizer, the above-mentioned p polarization first frequency band light is by described first plate polarizer;
This second plate polarizer, the described P polarization second frequency band light is by described second plate polarizer;
This first liquid crystal panel is reflected into the s polarization first frequency band optical image with the above-mentioned P polarization first frequency band light, and by described first plate polarizer reflection;
This second liquid crystal panel is reflected into the s polarization second frequency band optical image with the above-mentioned p polarization second frequency band light, and by described second plate polarizer reflection;
This color-combination prism is accepted above-mentioned s polarization first frequency band optical image and the s polarization second frequency band optical image.Described first plate polarizer, the second plate polarizer transmission p light beam, reflection s light beam.
The present invention second comprises the optical system of two biliquid crystal panel color splitting and mixings, is fit to comprise that the p polarization first frequency band light, the s polarization second frequency band light convert s polarization first frequency band optical image and the p polarization second frequency band optical image to, comprising:
This plate polarizer, the described p polarization first frequency band light are by this plate polarizer, and the described s polarization second frequency band light is by this plate polarizer reflection;
This first liquid crystal panel is reflected into the p polarization second frequency band optical image with the described s polarization second frequency band light, and this p polarization second frequency band optical image is by described plate polarizer;
This second liquid crystal panel is reflected into the s polarization first frequency band optical image with the described p polarization first frequency band light, and this s polarization first frequency band optical image reflects by described plate polarizer; Described plate polarizer transmission p light beam, reflection s light beam.
The present invention comprises that also the optical system or first of above-mentioned three liquid crystal panel color splitting and mixings comprises the crystal projection imaging system of the optical system of two biliquid crystal panel color splitting and mixings, and this system comprises: a light-source system, send the p polarized light; The described optical system that above-mentioned p polarized light is converted to the color splitting and mixing of a color image; And a projection lens, projection is from the above-mentioned color image of the optical system of above-mentioned color splitting and mixing.Wherein this light-source system also comprises: an emission one is the light source of polarized light not: one changes by the magnification change optical transition system of the not polarized light size of above-mentioned light emitted; And a polarization conversion system, convert above-mentioned not polarized light to the p polarized light.
The present invention comprises that also second comprises the crystal projection imaging system of the optical system of two biliquid crystal panel color splitting and mixings, and this system comprises: a light source, send the p polarization first frequency band light, the s polarization second frequency band light; The described optical system that the above-mentioned p of the sending polarization first frequency band light, the s polarization second frequency band light is converted to corresponding s polarization first frequency band optical image and the p polarization second frequency band optical image; And a projection lens, projection is from the above-mentioned s polarization first frequency band optical image and the p polarization second frequency band optical image of the optical system of above-mentioned color splitting and mixing.Wherein this light-source system also comprises: an emission one is the light source of polarized light not: one changes by the magnification change optical transition system of the not polarized light size of above-mentioned light emitted; And a polarization conversion system, convert above-mentioned not polarized light to the p polarization first frequency band light, the s polarization second frequency band light.
Owing to adopt high conversion, but flexible design, undersized plate polarizer carry out light path design, the present invention has the following advantages and is:
1. optical design is flexible, because this plate polarizer can be accepted light cone angle greater than 20 °, and in the wide-angle place good performance of work the optical design of imaging system is not restricted.Thereby also can improve the size and the operation of display when can utilize conventional light source to carry out light path design.
2. size is little and in light weight.Because the present invention adopts plate polarizer, volume is little and in light weight.
3. Heat stability is good.Because the long-time radiation that can not bear high temperature and light source of modern polarization deciliter light prism, after connecting light, can in polarizer, produce very high thermal gradient immediately like this and cause thermally induced birefringence, this thermally induced birefringence return the string that causes between the polarization around.And the plate polarizer that the present invention adopts can high temperature resistantly reach more than 120 degree, and has thermal stability preferably.
4. resolution and contrast are better.For projection device, the high density information image that effectively is placed on light source on the screen and on screen, obtains high resolving power and contrast, this all requires the product of p-polarization transmission rate and s-polarized reflectance must be big, the plate polarizer that the present invention adopts can satisfy as above requirement substantially, and makes light source collect light acceptance angle conversion efficiency maximum greatly the time.Resolution and contrast are better.
Description of drawings
The present invention is further described below in conjunction with drawings and Examples.
Fig. 1 is the light path principle figure of known beam splitting system.
Fig. 2 (a), Fig. 2 (b) are the of the present invention one light path synoptic diagram that comprises the optical system of three liquid crystal panel color splitting and mixings.
Fig. 3 a and 3b are the s of plate polarizer and the transmitance and the reflectivity of p polarimetry.
Fig. 4 is the of the present invention first light path synoptic diagram that comprises the optical system of two liquid crystal panel color splitting and mixings.
Fig. 5 is the of the present invention second light path synoptic diagram that comprises the optical system of two liquid crystal panel color splitting and mixings.
Fig. 6 comprises the synoptic diagram of LCD projecting system of the optical system of two biliquid crystal panel color splitting and mixings for using the optical system or first comprise three liquid crystal panel color splitting and mixings.
Fig. 7 comprises the LCD projecting system of the optical system of two biliquid crystal panel color splitting and mixings for use second.
Embodiment
Fig. 2 (a) is of the present invention one optical system that comprises three liquid crystal panel color splitting and mixings, shown in Fig. 2 (a), the optical system 30 of this colored color splitting and mixing comprises: one first color selector 31, one first plate polarizer 32, one second plate polarizer 33, one first liquid crystal panel 34, one second liquid crystal panel 35, one the 3rd liquid crystal panel 36, a phase delayer 37 and a color-combination prism 38.
In this embodiment of the present invention, wherein then via the s polarized green light g2 of these first plate polarizer, 32 reflections, the blue light b2 of above-mentioned s polarization state throws via second plate polarizer 33 by the ruddiness r1 of 33 reflections of second plate polarizer and p polarization state the green glow g1 of p polarization state by first plate polarizer 32.
With reference to Fig. 3 (a) and 3 (b), it is represented for the s of embodiment middle plateform polaroid 32 and 33 and the transmitance and the reflectivity of p polarimetry.For image projection system, as projector, if light source effectively is put on the screen, the product of the p-polarization of the s-polarization that is reflected and institute's transmission must be bigger.And on the other hand, for obtaining the required resolution of high signal density on the screen, importantly the inverse of product is very little.Be clear that from figure plate polarizer of the present invention satisfies these standards on whole spectrum, and do not produce Rayleigh resonance or other phenomenons produced degrades.Equally, all have suitable transmissivity and reflectivity at 30 degree, 45 degree and 60 degree as can be seen, and have big incident light cone angle as figure, and the added benefit of plate polarizer 32 and 33 luxuriant listing no longer just.
With reference to Fig. 2 (a), in an embodiment of the present invention, the light beam L0 of one p polarization is through first color selector 31, and the green glow g1 of p polarization state is by this color selector 31, and the ruddiness r1 of p polarization state and blue light b1 orientation are reflected by this color selector 31 perpendicular to incident beam L0;
The green glow g1 of described p polarization state reaches first liquid crystal panel 34 via 32 transmissions of first plate polarizer, is become s polarized green light image g2 by first liquid crystal panel, 34 reflection modulation;
Then, with reference to Fig. 2 (a), the ruddiness r1 of described p polarization state and the blue light b1 of p polarization state are via position retardation device 37 mutually, wherein the blue light b1 of p polarization state changes into the blue light b2 of s polarization state, the blue light b2 of this s polarization state arrives on second liquid crystal panel 35 by 33 reflections of second plate polarizer, via second liquid crystal panel 35 its reflection modulation is become the blue light image b3 of P polarization, then by second plate polarizer 33;
Wherein the ruddiness r1 of p polarization state is via position phase retardation device 37, and its polarization state does not change, and directly reaches the 3rd liquid crystal panel 36 by second plate polarizer 33, its reflection modulation is become the ruddiness image r2 of s polarization state.
Then color-combination prism 38 becomes the image L1 of LCD projector with the blue light image b3 of p polarization, the ruddiness image r2 and the s polarized green light image g2 of s polarization state.
Present embodiment can further be provided with one second mutually sluggish device 39 between the color-combination prism 38 and second plate polarizer 33, the blue light image b3 of P polarization is converted to the blue light image b4 of s polarization.
Shown in Fig. 2 (b), in order further to increase contrast of the present invention, present embodiment also can be replaced into color-combination prism 38 common polarization deciliter light prism 381, corresponding like this second phase delay device 39 converts third phase position delayer 391 to, wherein this third phase position delayer 391 converts the ruddiness image r2 of above-mentioned s polarization to the ruddiness image r3 of p polarization, thereby the ruddiness image r3 of the p polarization of incident polarization deciliter light prism 381 and the blue light image b3 of P polarization pass this polarization deciliter light prism 381, and s polarized green light image g2 enters imaging system by 381 reflections of this polarization deciliter light prism.
Fig. 4 is of the present invention 1 first optical system that comprises two biliquid crystal panel color splitting and mixings.As shown in Figure 4, the optical system 40 of this color deciliter comprises: one first color selector 41, one first plate polarizer 42, one second plate polarizer 46, one first liquid crystal panel 43, one second liquid crystal panel 44 and a color-combination prism 45.
Wherein p light beam L0 passes through this color selector 41 via first color selector, 41, one p polarization state green glow g1, and red, the indigo plant of another p polarization state are closed light m1 by these color selector 41 reflections;
With reference to figure 4, described p polarization state green glow g1 sees through first plate polarizer 42, injects on first liquid crystal panel 43, and this first liquid crystal panel 43 is s polarization state green glow image g2 with p polarization state green glow g1 reflection modulation;
With reference to figure 4, red, the indigo plant of described p polarization state is closed light m1 and is seen through second plate polarizer 46, is accepted reflection modulation by second liquid crystal panel 44 and becomes red, the indigo plant of s polarization state to close optical image m2;
With reference to figure 4, red, indigo plant that light-combining prism 45 is accepted s polarization state green glow image g2 and s polarization state are closed light m2 image becomes the image L1 of LCD projector.
Fig. 5 is of the present invention 1 second optical system that comprises two biliquid crystal panel color splitting and mixings.Present embodiment is the lower embodiment of a cost, wherein only comprises two liquid crystal panels 51,52 and a plate polarizer 53 in this optical system 50.
When light beam L0 input, wherein red, the indigo plant of p polarized green light g1 and s polarization is closed light m1 incident plate polarizer 53, this plate polarizer 53 of p polarized green light g1 transmission wherein, and this s polarization is red, indigo plant is closed light m1 by these plate polarizer 53 reflections;
Described liquid crystal panel 51 is red with the s polarization, to close light m1 reflection modulation be that red, the blue group photo of p polarization is as m2 to indigo plant;
Described display panels 52 becomes s polarized green light image g2 with described p polarized green light g1 reflection modulation, and reflects by described plate polarizer 53;
Then, red, the blue group photo of p polarization becomes the image L1 of LCD projector as m2 and s polarized green light image g2.
Fig. 6 comprises that for use is above-mentioned the optical system or first of three liquid crystal panel color splitting and mixings comprises the LCD projecting system of the optical system of two biliquid crystal panel color splitting and mixings.As shown in Figure 6, this LCD projecting system 60 comprises the optical system 64 and a projection optical system 65 of a light source 61, a magnification change optical transition system 62, a polarization conversion system 63, a color deciliter.
With reference to figure 6, one light source 61 emission one is not behind the polarized light L1, one magnification change optical transition system 61 changes the size of the not polarized light L1 of above-mentioned light emitted, then, above-mentioned not polarized light L1 becomes p polarized light L2 by these polarization conversion system 63 conversions, then, and after above-mentioned p polarized light enters the optical system 64 of color splitting and mixing, modulation produces color image L3, after the above-mentioned projection optical system 65 of color image L3 incident.The above-mentioned color image L3 of above-mentioned projection optical system 65 emissions.
Fig. 7 comprises the LCD projecting system of the optical system of two biliquid crystal panel color splitting and mixings for use above-mentioned second.As shown in Figure 7, this LCD projecting system 70 comprises the optical system 74 and a projection optical system 75 of a light source 71, a magnification change optical transition system 72, a polarization conversion system 73, a color deciliter.
With reference to figure 7, one light source 71 emission one is not behind the polarized light L1, one magnification change optical transition system 71 changes the size of the not polarized light L1 of above-mentioned light emitted, then, phase delay device 731 by this polarization conversion system 73, convert above-mentioned not polarized light L1 to the p polarization first frequency band light and the s polarization second frequency band light L2, then, after above-mentioned p polarization first frequency band light and the s polarization second frequency band light L2 enter the optical system 74 of color splitting and mixing, modulation produces s polarization first frequency band light and the p polarization second frequency band optical image L3, after s polarization first frequency band light and the above-mentioned projection optical system 75 of the p polarization second frequency band optical image L3 incident.Above-mentioned projection optical system 75 above-mentioned s polarization first frequency band light of emission and the p polarization second frequency band optical image L3.
By the optical system of color splitting and mixing of the present invention, owing to adopt plate polarizer to have high permeability and high reflectance, and adjustable angle and the little characteristics of volume, this projection optical system has:
1. wide acceptance angle because this plate polarizer can be accepted the light cone angle greater than 20 degree, is collected light acceptance angle conversion efficiency maximum when big from light source like this.
2. optical design is flexible, receives bigger cone angle and makes in the work of wide-angle place well, and this performance is not restricted the optical design of imaging system.Wide range makes the deviser other optical elements may be arranged on suitable position simultaneously, thereby improves the size and the operation of display.
3. size is little and in light weight.Conventional art requires to use polarization deciliter light prism cube, and these cubes itself have huge weight and volume.
4. Heat stability is good.Modern light source produces very high thermal gradient immediately in polarization deciliter light prism after connecting light.This thermal gradient can cause thermally induced birefringence, and thermally induced birefringence can cause between the polarization string around.And the long-time irradiation of high light causes some material to change character (flavescence by photooxidation usually).Therefore, the long-time radiation that needs polarization deciliter light prism can bear high temperature and light source, and the plate polarizer that the present invention adopts can high temperature resistantly reach more than 120 degree.
The above person only is most preferred embodiment of the present invention, is not to be used to limit the scope of the invention, and all equivalences of being done according to the present patent application claim change or modify, and are all the present invention and contain.