CN100507706C - LCD stereo projector polarization management system - Google Patents

Abstract

The invention belongs to the LCD stereo projection display field. At present, there are mainly two LCD stereo projection display modes: single projector mode and two-projector mode. And the natural light emitted from the projector light source is converted into partial polarized light through PCS(Polarization conversion system), and the polarized light is color-separated by dichroic mirror and then irradiates R, G and B LCD panels, respectively, and R, G and B lights are merged by X-Cube and then imaged to screen through projection objective; the polarizing states of the R, G, and B lights outputted from the X-Cube are orthogonal, and the polarizer at the outlet of the projector can not assure output of all R, G and B lights so that light energy is lost by 50%, thus affecting light energy utilization ratio and service life of stereo projector. And the invention adopts a polarization management system, making the R, G and B lights outputted from the X-Cube converted into the lights with the same polarization state, and the direction of transmission axis of linear polarizer at the outlet of the projector and the vibrating direction of incident light are the same so as to raise light energy utilization ratio.

Description

The LCD stereo projector polarization management system

[technical field]

The invention belongs to the LCD stereo projection display field, particularly two LCD projector stereo projection display field.

[background technology]

LCD projector is operated under the polarized light state.The natural light that sends from light source is converted into partial poolarized light through PCS (Polarization conversion system), through shining red, green, blue L respectively after the dichroic mirror color separation, CD Panel is imaged onto on the screen by projection objective through X-Cube is synthetic.At present, the implementation of LCD stereo projection display mainly contains two kinds: the implementation of the implementation of separate unit projector and two projectors.The implementation of separate unit projector is that the output port in projector is provided with a linear polarizer, alternately export the image that two width of cloth have certain parallax by computing machine, the observer cooperates stopping of the secondary control of a liquid crystal shutter glasses synchronously right and left eyes light or passes through, because the persistence of vision of human eye is a synthetic width of cloth stereo-picture in brain, the refresh rate of image be projector at ordinary times image refresh rate 1/2, scintillation is arranged.The implementation of two projectors is that the luminous energy output port every projector is provided with a mutually orthogonal linear polarizer respectively, and the observer wears the polaroid glasses of a secondary quadrature, realizes the demonstration of stereo-picture.Because from R, B and the G polarization of light attitude quadrature of the synthetic output of X-Cube, the polaroid of projector's output port can't guarantee whole outputs of R, B and G light, optical energy loss 50%, influence the utilization factor of luminous energy and the serviceable life of stereo projector.

[summary of the invention]

The technical matters that the present invention solves is to avoid entering in the prior art R, the B of polaroid of projector's output port and G polarization of light attitude quadrature and cause optical energy loss, provides a kind of LCD stereo projector polarization management system to improve the efficiency of light energy utilization.

For being provided, the LCD stereo projector polarization management system that provides comprises linear polarizer, X-Cube, projection lens and LCD Panels, described projection lens is between described X-Cube exit facet and linear polarizer, described LCD Panels is positioned at the described X-Cube plane of incidence one side, also comprise the polarization management device, described polarization management device is between described X-Cube exit facet and projection lens, make the light that is converted to same polarization state from the light of X-Cube output, and the direction of vibration of described same polarization state light is identical with the light transmission shaft of described linear polarizer.

Wherein, polarization converter device is the birefringence device, is a wave plate.The design concept of polarization converter device is: the centre wavelength of establishing R, G, B is respectively h, h, location.If the ordinary refraction index of a polarization converter device is n., the refractive index of extraordinary ray is ne.In order to make R, G, B be converted to same polarization state, make

$(n_e-n_o)\·d=k\·{\mathrm{\λ}}_1=(k+\frac{1}{2})\·{\mathrm{\λ}}_2=(k+1)\·{\mathrm{\λ}}_3---\left(1\right)$

D is the thickness of wave plate; K is an integer.Thickness is the central wavelength lambda of the wave plate of d with respect to R, B ₁, λ ₃Be full-wave plate, with respect to the central wavelength lambda of G ₂Be half-wave plate.Central wavelength lambda through G behind such polarization converter device ₂Polarization state rotated 90 °, and the central wavelength lambda of R, B ₁, λ ₃Polarization state constant.Make the spectral characteristic of wave plate be similar to a square wave by the achromatism design.

Equally, make

$(n_e-n_o)\·d=(k+\frac{1}{2})\·{\mathrm{\λ}}_1=k\·{\mathrm{\λ}}_2=(k+\frac{3}{2})\·{\mathrm{\λ}}_3---\left(2\right)$

The polarization state of R, B has been rotated 90 °, and the polarization state of G does not become.Make the light that is converted to same polarization state from the light of X-Cube output, the light transmission shaft of the linear polarizer of projector's output port is identical with the direction of vibration of incident light, has improved the efficiency of light energy utilization.The output light of two projectors, vertical by the conversion direction of vibration of polarization converter device, the polaroid by output port becomes two linearly polarized lights that direction of vibration is vertical respectively, can watch stereo-picture by the polaroid glasses of light transmission shaft quadrature.

[description of drawings]

Fig. 1 is the perspective view of two projectors of the present invention.

Fig. 2 is the index path of first projector of the present invention.

Fig. 3 is the index path of the used polarization management system of first projector.

Fig. 4,5 is respectively the used polarization management device incident of first projector's polarization management system and the spectral curve of emergent ray.

Fig. 6 is the index path of the polarization management device of second projector's use.

Fig. 7 is the spectral curve of the used polarization management device emergent ray of second projector.

Fig. 8 is the another kind of implementation of the polarization management device of second projector's use.

[embodiment]

Fig. 1 is the synoptic diagram of stereo projector, and it is made up of two projectors 101,102, and 103 for receiving screen, requires screen can not destroy the polarization of incident light attitude.These two projectors send same width of cloth image parallax, light direction of vibration quadrature respectively, and the polaroid glasses by the light transmission shaft quadrature are by the synthetic width of cloth stereo-picture of human eye.

Fig. 2 is the index path of first projector 201.204 is the lamp source, and 205 are filter ultraviolet/infrared glass; 206,207 is fly's-eye lens; 208 is PCS, and 209,221,212,214,225,217 form illumination section illumination R, G, B Panel 219,223,227; 210,211 is the dichroic dichronic mirror; 213,215,216 is catoptron; 222,224,226,228,218,220 is polaroid; 229 is X-Cube; 230 are popular in bluish-green spectro-film for counter, and 231 is anti-blue saturating red green spectro-film; 232 is the polarization management device, and it makes the polarization converted of R, G, B is the P ripple; 233 is projection lens; 234 is linear polarizer, and its light transmission shaft is identical with the direction of vibration of P ripple.

Fig. 3 is the fundamental diagram of first projector's polarization management device.The polarization state of R, B is the S ripple in the incident light; The polarization state of G is the P ripple.Polarization state through polarization management device 332 back R, G, B is all the P ripple, and the light transmission shaft of the polaroid of projector's output port is identical with the direction of vibration of incident ray.

Fig. 4,5 is respectively the spectral curve that incides polarization management device 332 and emergent ray.The polarization state of R, B and G is vertical as can be seen from Figure 4; The polarization state of R, G, B is identical as can be seen from Figure 5.

Fig. 6 is the polarization management device 632 work synoptic diagram that second projector 102 uses.The polarization state of emergent light G has been rotated 90 °, and is vertical with the polarization state of the polarization management device that uses in the projector 101.

Fig. 7 is the output spectrum curve map of polarization management device 632, and the polarization state of exporting light is as can be seen compared with 332 and rotated 90 °.

Fig. 8 is the another kind of implementation of the polarization management device of projector's 102 uses: 932 is the polarization management device that first projector 101 uses, and 935 is 1/2 wave plate, and it makes the polarization of incident light attitude rotate 90 °.

Claims (4)

1, a kind of LCD stereo projector polarization management system, comprise linear polarizer, X-Cube, projection lens and LCD Panels, described projection lens is between described X-Cube exit facet and linear polarizer, and described LCD Panels is positioned at the described X-Cube plane of incidence one side, it is characterized in that:

Also comprise the polarization management device, described polarization management device is between described X-Cube exit facet and projection lens, make the light that is converted to same polarization state from the light of X-Cube output, and the direction of vibration of described same polarization state light is identical with the light transmission shaft of described linear polarizer.

2, LCD stereo projector polarization management system as claimed in claim 1 is characterized in that:

Described polarization management device is a wave plate, and it is a half-wave plate with respect to the centre wavelength from the color G light of X-Cube output, is full-wave plate with respect to the centre wavelength from color R, the B of X-Cube output; Or:

Described wave plate is a full-wave plate with respect to the centre wavelength from the color G light of X-Cube output, is half-wave plate with respect to the centre wavelength from color R, the B of X-Cube output.

3, LCD stereo projector polarization management system as claimed in claim 1, it is characterized in that: described polarization management device comprises two wave plates, one of them wave plate will be converted to the light of same polarization state from the light of X-Cube output, and another wave plate is converted to the polarization direction of the light of described same polarization state identical with the light transmission shaft of described linear polarizer.

4, LCD stereo projector polarization management system as claimed in claim 1 is characterized in that: further comprise the polaroid that is positioned at LCD Panels light incident side and exiting side, make incident light and emergent light be converted to linearly polarized light.

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