[background technology]
In known technology, for the three primary colors (red, blue, green) that will constitute the luminous point pixel are projected on the camera lens, and reach preferable development quality, the structure of single-lens projection display equipment in the past roughly as shown in Figure 1, but the light beam of light source 10 that produced of a lighting device of this single-lens projection display equipment 1 treatment fluid crystal display just, light beam 10 after will handling is again sent best image quality after projecting to a camera lens 11, and aforementioned light beam 10 comprises one first coloured light 101, one second coloured light 102 and one the 3rd coloured light 103 that can synthesize from light.And projection display equipment 1 comprised in the past: one first light polarization selector 12, a polarization splitting prism 13, one double-colored Amici prism 14, one first reflective light valves 15, one second reflective light valves 16, one the 3rd reflective light valves 17, one second light polarization selector 18 and a Polarizer 19.
The ColorSelectTMFilters product that aforementioned lights polarization selector 12,18 can use ColorLink company to make, the effect of these light polarization selectors 12,18 is the polarization state of being scheduled to coloured light (as green light) can be changed, but does not influence the polarization state of other color.
And but the coloured light of these polarization splitting prism 13 vertical reflection S polarizations and allows the coloured light of P polarization directly penetrate, 14 of double-colored Amici prisms be select to allow different colours the coloured light reflection or pass through, be to allow first coloured light 101 pass through in Fig. 1, allow 102 reflections of second coloured light.And the function of first and second light polarization selector 12,18 is: will be scheduled to the conversion that coloured light is made polarization state, conventional art with Fig. 1 is an example, this first and second light polarization selector 12,18 can be done polarization converted to the 3rd coloured light 103, make it convert the P polarization to by the S polarised light, and Polarizer 19 is to allow the light transmission of P polarization enter camera lens 11, but absorbs the light of S polarization.
Still consult Fig. 1, when the light beam 10 of S polarization is entered by the first light polarization selector 12, have only the 3rd coloured light 103 can be converted into the P polarization, all the other first and second coloured light 101,102 are still kept the S polarization, wherein S polarization first coloured light 101 is through polarization splitting prism 13 time, can pass through double-colored Amici prism 14 directive first reflective light valves 15 more then to the direction vertical reflection of double-colored Amici prism 14.When first reflective light valves 15 is opened, aforementioned S polarization first coloured light 101 can change over the P polarization and double-colored Amici prism 14 is passed through in reflection, be subjected to the influence of polarization splitting prism 13 this moment for P polarization light characteristic, most of (about 90%) P polarization first coloured light 101 enters camera lens 11 through the second light polarization selector 18, Polarizer 19 again by this polarization splitting prism 13.And small part (about 10%) forms together partially that light leak 104 reflexes to the first light polarization selector 12, Here it is path that first coloured light 101 advances.
Identical reason, second coloured light 102 that is the S polarization equally is when advancing, also be through the double-colored Amici prism 14 of the reflection directive of the first light polarization selector 12, polarization splitting prism 13, but vertical directive second reflective light valves 16 of reflection through this double-colored Amici prism 14, when second reflective light valves 16 is opened, all S polarization second coloured light 102 can change over the P polarization, then through reflecting back into double-colored Amici prism 14, most of P polarization second coloured light 102 can enter camera lens 11 via the second light polarization selector 18, Polarizer 19 at last by polarization splitting prism 13.Small part P polarization second coloured light 102 can form the direction that the inclined to one side light leak 105 in another road reflexes to the first light polarization selector 12.That is to say, the polarization state of second coloured light 102 is identical with first coloured light 101, therefore, these two strands of coloured light, 101,102 major parts can project camera lens 11, the inclined to one side light leak 104,105 that small part forms can be to reflect therefore not influence of the image quality of 104, the 105 pairs of camera lenses 11 of inclined to one side light leak that produce with camera lens 11 vertical directions.
Cooperate Fig. 2, it is the schematic diagram of advancing of the 3rd coloured light on a kind of single-lens in the past projection display equipment, projection display equipment 1 was when handling the 3rd coloured light 103 in the past, the 3rd coloured light 103 is through the first light polarization selector 12 time, can change the P polarization into by S optical rotation originally, but be subjected to the influence of polarization splitting prism 13 for P polarization light characteristic, the 3rd coloured light 103 approximately has 90% by polarization splitting prism 13 arrival the 3rd reflective light valves 17, but nearly 10% P polarization the 3rd coloured light 103 can reflection be invested double-colored Amici prism 14, causes so-called inclined to one side light leak 106.This phenomenon may be because of the range of choice of the 3rd coloured light 103 wavelength, and enter first reflective light valves 15 and/or second reflective light valves 16, again along with these light valves 15,16 conducting together projects camera lens 11 along the travel path reflection of first coloured light 101 or second coloured light 102, because Polarizer 19 can only absorb a kind of light of polarization state, it is to absorb the S polarised light in the design of display unit 1 in the past, therefore, the inclined to one side light leak 106 that P polarization the 3rd coloured light 103 is produced can't be absorbed, and can directly project camera lens 11, cause the reduction of image contrast, and imaging effect is undesirable, and Here it is, and single-lens in the past projection display equipment 1 produces one of not good reason of image display quality.
Still consult Fig. 2, as previously mentioned, be subjected to the influence of polarization splitting prism 13 characteristics, approximately have only 90% P polarization the 3rd coloured light 103 meeting trends of purchasing the 3rd reflective light valves 17, when the 3rd reflective light valves 17 was opened, the 3rd coloured light 103 can change the S polarization into by the P optical rotation, because polarization splitting prism 13 can reflect the light of S polarization, therefore, the 3rd coloured light 103 after the conversion polarization state can vertically be invested the second light polarization selector 18, Polarizer 19, advances to the direction of camera lens 11 again.When the 3rd reflective light valves 17 is closed, though its purpose makes the 3rd coloured light 103 no longer invest camera lens 11, but because the 3rd coloured light 103 presents the P polarization, this P polarization the 3rd coloured light 103 can arrive polarization splitting prism 13 with the attitudinal reflexes of P polarization equally, but be subjected to the influence of polarization splitting prism characteristic, above-mentioned P polarization the 3rd coloured light 103 has only about 90% can advance toward Fig. 2 left direction, and about 10% P polarization the 3rd coloured light 103 can form an inclined to one side light leak 107 toward the direction vertical reflection of Fig. 2 top second light polarization selector 18, the inclined to one side light leak 107 of this P polarization is owing to can't be absorbed by Polarizer 19, therefore, the inclined to one side light leak 107 of the P polarization of these improper reflections can directly be invested camera lens 11, cause to occur the 3rd coloured light 103 faint but that should not present on the camera lens 11, cause the undesirable of display 1 image display quality.
[embodiment]
Consult Fig. 3, the projection display equipment 3 of present embodiment can enter for a light beam 2, project on the vertically disposed camera lens 20 after again light beam 2 being handled, above-mentioned light beam 2 comprises: first coloured light, 21, one red second coloured light 22 of a green, an and blueness the 3rd coloured light 23, these first, second and third coloured light 21,22,23 all are that the form with the P polarization exists, but deliver to camera lens 20 with the form of S polarization.
The projection display equipment 3 of present embodiment comprises: a polarization converted device 31, a polarization splitting prism 32, one first double-colored Amici prism 33, one first reflective light valves, 34, one second double-colored Amici prism 35, one second reflective light valves 36, one the 3rd reflective light valves 37, a light polarization selector 38 and a Polarizer 39.This polarization converted device 31, be used for changing the polarization state of first coloured light 21 in the light beam 2, make first coloured light 21 change the S polarization into by the P optical rotation, it has the P light Polarizer 311 of a purifying light beam 2 polarization states, and one converts first coloured light 21 of P polarization the light polarization selector 312 of S polarization to.The feasible enforcement of above-mentioned polarization converted device 31 is a lot, in the design not with exceeding that present embodiment discloses.
This polarization splitting prism 32, first coloured light 21 and second and third coloured light of different polarization states can be opened in 22,23 minutes, at present embodiment, it can make S polarization first coloured light 21 vertically to the direction reflection in contrast to camera lens 20, and second and third coloured light 22,23 of P polarization can pass through this prism 32.
This first double-colored Amici prism 33 parallelly with polarization splitting prism 32 and is positioned at direction away from camera lens 20 side by side, and it can make the light of a certain color pass through, the light reflection of all the other colors.At present embodiment, this first double-colored Amici prism 33 can make the first green coloured light 21 pass through, and makes second and third coloured light 22,23 reflections.
This first reflective light valves 34, with the first double-colored Amici prism 33 uprightly side by side, and be positioned at tossing about of polarization splitting prism 32, it can change polarization state of light, just under the state of opening, S polarization first coloured light 21 that is incident upon on first reflective light valves 34 can be changed into P polarization first coloured light 21.But under first reflective light valves, 34 closing state, this S polarization first coloured light 21 can reflect but polarization state does not change.
This second double-colored Amici prism 35, be positioned at the top of polarization splitting prism 32, just be positioned on the path that the P polarization light advances, and select passing through of light or reflect with color, when second and third coloured light 22,23 during simultaneously through the second double-colored Amici prism 35, wherein red P polarization second coloured light 22 can pass through prism 35,23 reflections of blue P polarization the 3rd coloured light.
This second reflective light valves 36 is positioned at the top of the second double-colored Amici prism 35, is used for reflecting and optionally changing simultaneously the polarization state of second coloured light 22, and function is identical with first reflective light valves 34, no longer explanation.
The 3rd reflective light valves 37 is positioned at the left of the second double-colored Amici prism 35, is used for reflecting and/or optionally changing the polarization state of the 3rd coloured light 23, and its function is identical with first reflective light valves 34.
This light polarization selector 38, parallel 20 on polarization splitting prism 32 and the camera lens that is positioned at makes P polarization first coloured light 21 convert the S polarization to.
This Polarizer 39 between 20 on light polarization selector 38 and camera lens, is used for absorbing the light of P polarization.
Consult Fig. 3, when P polarization first coloured light 21 process light polarization selectors 312, can convert S polarization first coloured light 21 to, this first coloured light 21 is through the reflection of polarization splitting prism 32, the vertical directive first double-colored Amici prism 33, because this first double-colored Amici prism 33 can allow the first green coloured light 21 pass through, therefore, S polarization first coloured light 21 can project first reflective light valves 34 through this.When first reflective light valves 34 is opened, this S polarization first coloured light 21 can reflect and change over P polarization first coloured light 21 invests the first double-colored Amici prism 33, though the polarization state of first coloured light 21 changes, but its color still is green, therefore green P polarization first coloured light 21 still can pass through the first double-colored Amici prism 33, and directive polarization splitting prism 32, because the characteristic of polarization splitting prism 32, P polarization first coloured light 21 of this moment about 90% can be passed through by polarization splitting prism 32, convert the S polarization to through light polarization selector 38 again, invest camera lens 20 video pictures with the form of S polarization first coloured light 21 through Polarizer 39 then.As previously mentioned, the light of P polarization is through polarization splitting prism 32 time, having about 10% first coloured light 21 can't be by forming the first inclined to one side light leak 211 one, this moment, this first inclined to one side light leak 211 can penetrate towards the direction of polarization converted device 31, that is to say, the direction of first inclined to one side light leak 211 projections is vertical with the direction that enters camera lens 20, can the video picture of camera lens 20 not exerted an adverse impact.
Consult Fig. 4, when first reflective light valves 34 is closed, originally S polarization first coloured light 21 that reflects by polarization splitting prism 32 and come, can be with identical polarization state reflection by the first double-colored Amici prism 33, the direction reflection that enters by light beam 2 via polarization splitting prism 32 again, this first coloured light 21 is because vertical with the direction that projects camera lens 20, and therefore, 21 pairs of projection images of first coloured light of this reflection are not influence also.
Consult Fig. 5, when second and third coloured light 22,23 enters polarization splitting prism 32, enter because it is a mode with the P polarization, second and third coloured light 22,23 of the P polarization of this moment about 90% can be by polarization splitting prism 32, and toward the direction projection of the second double-colored Amici prism 35.But be subjected to the influence of polarization splitting prism 32 characteristics, still have about 10% P polarization second, three coloured light 22,23 when projecting polarization splitting prism 32, direction vertical reflection toward the first double-colored Amici prism 33, and one second inclined to one side light leak 24 of formation, this second inclined to one side light leak 24 is owing to comprise red, blue double-colored second, three coloured light 22,23, these coloured light 22,23 can't be by specializing in the first double-colored Amici prism 33 that green glow passes through, therefore, second, three coloured light 22,23 when reflexing to the first double-colored Amici prism 33, can be once again toward direction (being exactly) reflection, so the second inclined to one side light leak 24 can not exert an adverse impact to the image tone of projection yet toward Fig. 5 top perpendicular to camera lens 20.
At the same time, second and third coloured light 22,23 by polarization splitting prism 32 can separate forming second coloured light 22 that passes through and the 3rd coloured light 23 of reflection when running into the second double-colored Amici prism 35.Wherein, red second coloured light 22 of P polarization is by this second double-colored Amici prism 35, can be directly by being incident upon second reflective light valves 36, and blue the 3rd coloured light 23 of P polarization can be because being provided with to the reflection of Fig. 5 left vertical of the second double-colored Amici prism 35, and to the direction projection of the 3rd reflective light valves 37.When second reflective light valves 36 is opened, P polarization second coloured light 22 can produce reflection because of second reflective light valves 36 and polarization state changes, that is to say, reflection back S polarization second coloured light 22 can be all by second double-colored Amici prism 35 and the directive polarization splitting prism 32, and then whole vertical duction directive light polarization selectors 38 and Polarizer 39, wherein, the impure P polarization light of only a few can be absorbed by Polarizer 39 in second coloured light 22, all invests camera lens 20 then.
Identical reason, when the 3rd reflective light valves 37 is opened, P polarization the 3rd coloured light 23 that projects the 3rd reflective light valves 37 can change into S polarization the 3rd coloured light 23, all reflex to the second double-colored Amici prism 35 then, because the 3rd coloured light 23 at this time is still by the blue light of second double-colored Amici prism 33 reflections, therefore, this S polarization the 3rd coloured light 23 can reflection be invested polarization splitting prism 32, and then invests camera lens 20 via light polarization selector 38 and Polarizer 39 completely.
More specifically say, under the state that second and third reflective light valves 36,37 is opened, 22,23 of second and third coloured light that enter with the P polarization can produce the second inclined to one side light leak 24 that is penetrated by Fig. 5 upper right side, and can produce the first inclined to one side light leak 211 that penetrates by Fig. 3 below together with first coloured light 21 that the S polarization form enters, therefore these first and second inclined to one side light leak 211,24 can not cause bad influence to the image of projection because all vertical with camera lens 20.
Cooperate Fig. 6, when second reflective light valves 36 is closed, originally pass through P polarization second coloured light 22 of the second double-colored Amici prism 35, under the constant state of polarization state, still can pass through this second double-colored Amici prism 35, enter polarization splitting prism 32 then, identical reason with the form of P polarization, because about 90% P polarization second coloured light 22 can be discharged toward the direction that light beam 2 enters by polarization splitting prism 32, therefore most of P polarization second coloured light 22 can not exert an influence to camera lens 20.About in addition 10% P polarization second coloured light 22 is the 3rd inclined to one side light leaks 25 to camera lens 20 directions that reflect to form one via polarization splitting prism 32, though this road the 3rd inclined to one side light leak 25 advances towards the direction of camera lens 20, but because camera lens 20 and 32 of polarization splitting prisms are provided with the Polarizer 39 that absorbs the P polarization, therefore, P polarization the 3rd inclined to one side light leak 25 can be absorbed fully by Polarizer 39, still can not pass through camera lens 20.
Identical reason, when the 3rd reflective light valves 37 is closed, P polarization the 3rd coloured light 23 can directly reflex to the second double-colored Amici prism 35, reflex to polarization splitting prism 32 again, most of then P polarization the 3rd coloured light 23 is penetrated by the direction of Vertical camera lens 20, P polarization the 3rd coloured light 23 of fraction can form together the 3rd inclined to one side light leak 25 equally towards the direction ejaculation of camera lens 20, and is subjected to Polarizer 39 and absorbs and can't reach camera lens 20.The unlatching of above-mentioned each light valve 34,36,37 or close be subjected to the video picture color need control, therefore, the keying of each light valve 34,36,37 is not certain, but no matter each light valve 34,36,37 is under unlatching or closing state, the inclined to one side light leak that the P polarization is produced in the operation all can be reflected to the direction perpendicular to camera lens 20, perhaps before camera lens 20, just absorbed, can not pass through camera lens 20 fully by Polarizer 39.The present invention also can set up the assembly of strengthening contrast, for example 1/4 ripple plate at each light valve 34,36,37 and 33,35 adjacent of double-colored Amici prisms.
By above explanation as can be known, the present invention utilizes the cooperation between a polarization splitting prism and two double-colored Amici prisms, can improve the projection display really when utilization, and P polarization coloured light can produce the shortcoming that inclined to one side light leak and part are invested camera lens.The inclined to one side light leak of above-mentioned major part can improve the contrast and the image display quality of image really toward the direction refraction that is different from camera lens or the phenomenon of reflection.